Cameron announces 'same day' visa service for Indian students and businessmen as he rolls out red carpet in Mumbai trade mission 'No limit' to the number of Indians who want to study and work in UK Wants India to make it easier for British companies to do business there Current visa service can take more than three days to process applications More Indian students and businessmen will be welcomed into the UK, David Cameron announced today, as he scraps limits on immigration and speeds up the visa process. The Prime Minister made the announcement as part of a deal that means India will make it easier for British companies to do business in the sub-continent. He made the announcement after arriving in Mumbai ahead of the largest trade mission ever to travel overseas with a prime minister. David Cameron announced the new visa service and relaxed immigration riles as he speaks n Mumbai, India Speaking on the first day of his second visit to India as PM, Mr Cameron announced the creation of a new 'same-day' visa service for Indian businessmen. The speedier service in response to unhappiness with the current system which can take three days or more to process applications. David Cameron holds talks to Unilever employees at their headquarters in Mumbai He also said there was 'no limit' to the number of Indians who would be allowed to study at UK universities and stay on in graduate-level jobs after they qualified. Speaking to workers at the Mumbai headquarters of the Anglo-Dutch Unilever group, Mr Cameron said: 'Britain is one of the most open, easy-to-invest-in countries in the world. We are incredibly welcoming. I am very proud of the fact that it is an Indian company, Tata, that makes the Jaguars and Land Rovers that are taking the world by storm. 'They also roll most of our steel and own Tetley Tea - and you don't get any more British than Tetley Tea. I am very proud of that. Britain is an open economy and we encourage that investment. Mr Cameron made clear that in return, he wanted India to tear down outdated barriers to investment to help UK-based companies in areas like insurance and banking to establish a foothold in the fast-growing economy. I think, in return, we should be having a conversation about opening up the Indian economy, making it easier to do business here, allowing insurance and banking companies to do more foreign direct investment into the Indian economy. There are still many rules and regulations in the Indian economy associated with how you did things in the past which, if you change them, will make your economy grow and deliver more jobs, more wealth, more prosperity across your country. The Prime Minster said he wanted Britain and India to forge a 'a really special relationship' for the 21st century David Cameron launched an attack on 'aggressive' tax avoidance today. The Prime Minister said the Government wanted to keep business taxes low so long as businesses paid their fair share. But he said it would be 'difficult' for new laws to force companies to pay their taxes. Mr Cameron has made transparency over tax a key priority of Britain's presidency of the G8 group of world economic powers this year, after a series of controversies over the arrangements of huge companies which were shown to be paying little tax in the UK. He told an audience at the Unilever headquarters in Mumbai that the government are cutting the rate of corporation tax on company profits down to 21 per cent. He said: 'The message to business should be, "If we are cutting this rate of tax down to a good low level, you should be paying that rate of tax, rather than seeking ever more aggressive ways to avoid it."' I think the problem with that is that there are some forms of tax avoidance that have become so aggressive that there are moral questions that we have to answer about whether we want to encourage or allow that sort of behaviour. Some would say, "Just change the law to make aggressive avoidance illegal," but, with respect to my friends in the accountancy profession, it is difficult to do that. 'It's a good to have, but it goes both ways. We should look at the things we need to do to take our barriers down, and we hope your government will do the same. Mr Cameron is accompanied on his three-day trip by a delegation of more than 100 representatives of major corporations, small businesses and academic institutions, as well as football's Premier League, the London Underground and nine parliamentarians. He told his audience in Mumbai that he wants Britain's partnership with India to be 'a really special relationship' for the 21st century. 'Britain wants to be your partner of choice,' said Mr Cameron. We think there are huge ties of history and language and culture and business, but we think we have only just started on the sort of partnership we could build. Britain was 'rewriting the rules' in response to Indian business and government calls for easier access to high technology, he said. Mr Cameron said was discussing the prospects for a new corridor of development between Mumbai and Bangalore with the Delhi government. It would feature new towns and infrastructure, which could provide opportunities for British planners, architects, construction firms and finance specialists. He added: 'We are looking with your government at whether we can open up a whole corridor between Mumbai and Bangalore of growing towns and developments and work and plan that with you. With me, I have got architects, planners and private finance experts who can work out a complete solution, putting together all the things you need to have that infrastructure. On providing new infrastructure, Mr Cameron said his main advice was to 'start now', rather than delaying construction for years. He cited the example of the London Underground, which deteriorated for decades for lack of investment in upgrades. 'One thing I would say is, if you know you have got to build new infrastructure, even though you know it is going to take many years, start now,' he said. VIDEO: 'Come to our country quickly,' says Cameron at India summit