Gordon Brown condemned wildcat strikes as indefensible amid frantic efforts to prevent the row over the use of foreign labour escalating into mass industrial action.
The Prime Minister said he recognised people were 'worried' about jobs being taken by workers from other countries, but stressed that the UK was part of a 'single European market'.
He also sought to explain his pledge of 'British jobs for British workers', insisting he had only meant people would be given the skills to compete against other nationalities.
The comments, in an interview with the BBC's Politics Show, came as efforts continued to stop tensions spiralling out of control.
Officials from government departments, unions, employers and the mediation service Acas have been in frantic discussions following a series of wildcat strikes that erupted across the country on Friday.
The protests were prompted by a decision to bring in hundreds of Italian and Portuguese contractors to work on a new £200million plant at the giant Lindsey Oil Refinery at North Killingholme, North Lincolnshire. Unions claim Britons were not given any opportunity to apply for the posts.
Music courtesy of Joey Smith - Say Goodbye To Everything We Know
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