LEAD: Britain's Cameron faces referendum calls ahead of key EU summit

By Anna Tomforde Dec 7, 2011, 16:29 GMT

London - Prime Minister David Cameron came under growing pressure Wednesday to hold a referendum in Britain in the event of major changes to EU treaties being agreed at this week's crucial EU summit.

In an article for the Times newspaper, Cameron warned that Britain would block any proposed changes to EU treaties that would fail to protect its interests.

But Cameron said Britain would take a constructive attitude towards the discussions aimed at ending the crisis in the eurozone, which was a 'priority.'

However, his approach appeared to be undermined Wednesday by calls from senior Conservative politicians for a referendum to be held in Britain in the event of any EU treaty changes.

Boris Johnson, the Mayor of London and one of Cameron's key rivals in the Conservative Party, urged a referendum if the summit discussions should result in a 'new EU-wide treaty.'

Johnson described the current efforts to solve the eurozone debt crisis as a desperate attempt to 'patch' things together. 'I think we are in danger of saving the cancer and not the patient,' he said.

An open challenge to hold a referendum also came from cabinet minister Owen Paterson, the Northern Ireland secretary.

'If there was a fundamental change in our relationship, emerging from the creation of a new bloc which would be effectively a new country from which we were excluded, then I think inevitably there would be huge pressure for a referendum,' Paterson told the Spectator magazine.

Cameron has always insisted that a referendum would only be held if Britain was required to concede 'additional' powers to the EU.

He has, instead, threatened to veto reforms aimed at securing the future the single currency if 'British interests' were not protected.

These included measures to protect Britain's financial services, amid fears that the City of London financial centre could be hit by a possible transaction tax, and protections for the single market.

Cameron said Britain's demands would be 'practical and focused' - but he would not show a 'lack of steel' to fight for them.

Reflecting British fears that the 17 eurozone countries could agree new rules without the rest of the European Union, Cameron said the most 'credible' way of pushing Europe forward was to involve all 27 members.

Cameron is under strong pressure from Conservative eurosceptics to use the current crisis as an opportunity to redefine Britain's relations with the EU. But he has ruled out calls for a referendum or wholesale renegotiation of EU membership.

Recent apparent moves in Brussels to make treaty alterations without national ratification procedures have also raised alarm bells in Britain, where the European issue has the potential of splitting apart the Conservative-Liberal coalition government.

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