Boris Johnson in plea not to dismantle Tower of London poppies next week Extraordinary display of 888,246 ceramic poppies is due to be removed after Armistice Day next Tuesday The vast installation, Blood Swept Lands And Seas Of Red, wad created by ceramic artist Paul Cummins Officials from Historic Royal Palaces has encouraged people to postpone weekend visits to ease crowds Up to 4million are expected to visit the First World War tribute - which will raise £11.2million for charity People have been urged to delay their visit until later in the day and avoid weekends to ease overcrowding Tube stations closed and crowd control barriers put up to deal with huge numbers of people visiting the site All of the poppies have been sold for £25, and many will be hoping to receive them before Christmas But London Mayor Boris Johnson has called for it to be extended beyond next week to give more people a glimpse Boris Johnson today called for the removal of the Tower of London's field of ceramic poppies to be delayed, to give more time for people to see the stunning display. The London Mayor has issued a direct plea to organisers to extend the exhibition beyond next week's deadline of November 12, when up to four million people are expected to have paid tribute at the display of 888,246 poppies in the Tower's moat on the bank of the River Thames. The vast installation, Blood Swept Lands And Seas Of Red by ceramic artist Paul Cummins, has captured the public imagination as the nation marks 100 years since the outbreak of the First World War. All of the poppies have been sold, at £25 each, with buyers hoping to have them in time for Christmas. Big draw: The huge popularity of the ceramic poppies at the Tower of London, pictured tonight, has exceed the expectations of organisers, with tens of thousands of people queuing during the day and night to catch a glimpse Jaw-dropping: Members of the public stop to look at the ceramic poppies which form part of the art installation 'Blood Swept Lands and Seas of Red' by artist Paul Cummins at the Tower of London, which has been commissioned to mark the centenary of the First World War Charity money-spinner: All of the poppies have been sold, at £25 each, with buyers hoping to have them in time for Christmas. Poignant: More than 800,000 ceramic poppies have been planted in memory of British and Commonwealth soldiers killed in the First World War Popular: Crowds flocked again to see the the vast memorial despite warnings not to come because of overcrowding The installation has captured the public imagination as the nation marks 100 years since the outbreak of the First World War next Tuesday National memory: By next week's deadline of November 12 up to four million people are expected to have paid tribute at the display More time: Boris Johnson has called for the closure to be delayed to give more people chance to see the installation Meaningful: Many visitors have travelled from across the country to catch a glimpse of the memorial in the moat of the Tower The poppies have gradually been added in recent weeks, and has nearly reached completion ahead of Armistice Day on Tuesday, November 11. Historic Royal Palaces plans to then start the process of dismantling the exhibition. The poppies have been sold for charity, and people who have bought them have already been warned they will not get them until the New Year. But Mr Johnson has called for the closure to be delayed to give more people chance to see it, with many travelling from across the country to catch a glimpse. Mr Johnson told the Evening Standard said: 'The poppy field at the Tower is a unique and poignant focus of remembrance in this centenary year. It has grown rapidly in popularity, to such an extent that it is now a global visitor attraction. 'I'm keen to explore whether we can keep the exhibition open for longer, to give as many people as possible the chance to glimpse something so incredible, whilst easing the pressure on numbers.' Talks: A spokesman for the mayor said he was in discussion with Historic Royal Palaces about extending the exhibition for a further week. Sales: But Historic Royal Palaces said it was always the intention to begin sending the poppies to their new owners after Armistice Day Memorial: By November 11, there will be 888,246 ceramic poppies at the site, one for each British and colonial death during the First World War Dismantling: Eleven thousand volunteers will then begin removing the installation from November 12, Culture Minister Ed Vaizey said Funds: Royal British Legion said it hopes the sale of the poppies - which were available to buy for £25 each - will raise in excess of £15 million Delivery: Buyers of the poppies could be left disappointed if the arrival of theirs was postponed because of an extension to the memorial The vast installation, Blood Swept Lands And Seas Of Red, wad created by ceramic artist Paul Cummins to mark the WWI centenary Thousands of visitors have flocked to the Tower of London despite calls from organisers to cancel weekend visits because of overcrowding By November 11, when the display is due to be dismantled, up to four million people are expected to have seen it Tower Hill tube station has been closed and crowd control barriers set up to deal with the huge numbers of people who have flooded the area around the Tower of London moat Many ignored the pleas to delay their visit, turning up in the droves during half term and every day since London Mayor Boris Johnson, who sold poppies last week with actor Brian Blessed, has issued a plea to organisers to delay the process of removing the poppies A spokesman for the mayor said he was in discussion with Historic Royal Palaces, the agency which runs the Tower of London, about extending the exhibition for a further week. But Historic Royal Palaces said today that it was always the intention to begin sending the poppies - which have been sold to raise cash for charity - to their new owners after Armistice Day on November 11. A spokeswoman said: 'We have been overwhelmed by the support from the public for Blood Swept Lands And Seas Of Red, our installation of ceramic poppies in the moat at the Tower of London. It has always been intended that the poppies will be in place until November 11 and after this time they will be cleaned and sent out to all those that have purchased them. The transience of the installation is key to the artistic concept, with the dispersal of the poppies into hundreds of thousands of homes marking the final phase of this evolving installation. We are currently planning further ways in which the Tower of London will be marking the coming years of the centenary and the legacy of the poppies in the moat. The Queen and Prince Philip walked among the ceramic poppies last month, as volunteers continued the painstaking process of planting the thousands of poppies When the poppy field was first launched in August, the Duchess of Cambridge was one of the first high profile visitors to the site By November 11, there will be 888,246 ceramic poppies planted at the site, one for each British and colonial death during the First World War, which began 100 years ago. Eleven thousand volunteers will then begin removing the installation from November 12, Culture Minister Ed Vaizey said on Twitter. Royal British Legion said it hopes the sale of the poppies - which were available to buy for £25 each - will raise in excess of £15 million. Buyers of the poppies could be left disappointed if the arrival of theirs was postponed because of an extension to the memorial. Rehema Figueiredo, 23, from Balham, south London, who bought two, said she was expecting to receive hers not to long after Remembrance Day to pass them on as gifts. 'I bought two as presents for people who had relatives that were lost in the war and they will be most upset that they won't get their poppies in time. 'I bought mine maybe a month and a half ago so I've already been waiting that long for it to come and it's a bit disappointing to think that we will be waiting even longer.' The public were urged to postpone their visits to the poppy field last week due to overcrowding during the school half-term holiday. Phil Hufton, London Underground's chief operating officer, said Tower Hill station near the memorial had been 'extremely busy' and occasionally the station was being closed on police advice. Each night at sunset, the Last Post is played and a Yeomen Warder reads out the names of some of the Commonwealth soldiers who gave their lives in the First World War Transport for London has urged visitors to the Tower of London to travel to nearby Tube stations Aldgate or Aldgate East or take the DLR to Tower Gateway. Commuters have also been asked to consider travelling to London Bridge and then walk, cycle or take a bus. Motorists have also been advised not to drive in the area. One beneficiary from the sale of the poppies, military charity SSAFA, backed the closure of the exhibition next week. A spokeswoman said: 'Its transience is part of the overall artistic concept. Given that around four million people are thought to have visited the poppies, we appreciate that Historic Royal Palaces now needs to fulfil its obligation to those who have bought a poppy, and thereby generously supported the charities who are benefiting from the proceeds from their sale.