text: Philip Hammond pledged to protect the Falklands from ‘Argentinian bullying’ last night as the country began legal action against British companies exploring for oil off the islands. It follows a provocative speech by Argentinian president Cristina Fernandez de Kirchner, prompting the Foreign Office to summon her ambassador for a dressing down. Buenos Aires responded by accusing three British oil firms of working without permission. The Argentine government said it was taking legal action against three British and two US companies for ‘exploration activities for fossil fuels on the Argentine continental shelf without obtaining the corresponding authorisation’. The legal complaint listed Rockhopper Exploration, Premier Oil, Falkland Oil and Gas Limited and US firms Noble Energy and Edison International – accusing them of sending a semi-submersible rig to explore a basin 120 miles north of the islands ‘subjected to the illegitimate British occupation’. Argentina's President Cristina Fernandez de Kirchner (centre) poses with veterans of the 1982 Falklands War, during the commemoration of the 33rd anniversary of the conflict last week . It also warned the rig’s owner, Greece-based firm Ocean Rig, that it could face ‘legal consequences’ over the drilling. The diplomatic row over the fate of the Falklands has worsened in recent weeks, after the UK Government pledged to invest £180million in the islands’ defences over the next ten years. President Fernandez de Kirchner last week promised: ‘We will see the islands form part of our territory again. It’s not just wishful thinking.’ Her remarks came on the 33rd anniversary of Argentina’s invasion of the Falklands, leading to a conflict that cost 250 British and 650 Argentinian lives. Last night Foreign Secretary Mr Hammond said: ‘Cristina Kirchner’s threats against those who do business with the Falkland Islands are as hollow as they are illegal. The islanders have a perfect right to develop their oil and gas industry – and they can rely on us to protect them from Argentinian bullying as they do so.’ Alicia Castro, Argentine ambassador to the UK, was summoned by the Foreign Office on Wednesday. Yesterday, in a tit-for-tat move, Argentine deputy foreign minister Eduardo Zuain summoned the UK ambassador to Buenos Aires, John Freeman, to complain about recent spying revelations by Edward Snowden. Daniel Filmus, minister for the Malvinas – as Argentina calls the Falklands – said his government would try to block further oil exploration. ‘We want the owners of the companies to be tried according to Argentine laws and international statutes,’ he said, adding that this could involve ‘an Argentine judge issuing an arrest warrant against those who operate illegally in Argentine waters’. Although Falkland residents overwhelmingly voted to stay British in a recent referendum, Buenos Aires claims the islands and surrounding waters belong to Argentina. Defence Secretary Michael Fallon, pictured today, last month announced plans to boost the UK's military defences of the Falkland Islands . Last week, the Argentine president and ambassador Alicia Castro publicly attacked the UK Government's plan to boost defences on the South Atlantic islands. Mrs Kirchner's government has also suggested that British oil firms could be prosecuted if they start drilling in the waters around the islands without formal permission from Argentina. The outspoken Argentine president's latest comments came on April 2, the 33rd anniversary of the start of the 1982 Falklands War. She reportedly said: 'International law and dialogue, not militarisation, are the path to a reunion and sovereignty. 'We will see the islands form part of our territory again. It's not just wishful thinking.' But a Foreign Office spokesman attacked the provocative intervention. He said: 'The UK has no doubt about its sovereignty over the Falkland Islands and surrounding maritime areas, nor about the Falkland Islanders' right to decide their own future. 'We object strongly to recent statements by the Argentine president and the Argentine ambassador to London and so summoned the ambassador to account for these.' It came after the British government last week dismissed the threat of prosecution against oil and gas firms working off the Falkland Islands. Three British firms - Premier Oil, Rockhopper Exploration and Falkland Oil & Gas - announced that they had found oil and gas in a remote field north of the islands, which are claimed by Argentina. Last month, Defence Secretary Michael Fallon said the Government was preparing to 'beef up' defences in the Falklands. He said two Chinook helicopters and an upgraded surface-to-air missile system will be part of a new defence package for the islands. Mr Fallon said: 'We've been reviewing the defence of the Falklands, we do that every so often, and I'm going to be announcing to parliament later today how we are going to beef up the defences there, how we are going to modernise our defences, and to reassure the islanders that we are absolutely committed to their right to remain British and to the defence of the islands... 'We are absolutely committed to defending the Falklands. The threat to the Falklands has not gone away.' He said 'modernising what we are doing' in the Falklands was a response to the threat of Russia. 'Russia has changed. We hoped Russia would be a partner to us – a normal trading partner that respected the rules of the international system, but it's turned out that Russia is directly competing against and is becoming much more aggressive in lots of different parts of the world, and we have to respond to that.'
target: Argentine president Cristina Fernandez de Kirchner said islands not British .
  She said: 'We will see the islands form part of our territory again'
  Also publicly attacked plan to boost defences on the South Atlantic islands .
  Claimed she would sue oil firms drilling in the waters around the islands .