LONDON (Reuters) - Politicians who want Britain to withdraw from the European Union are "false patriots" who act against Britain's national interests, Deputy Prime Minister Nick Clegg will say in a speech on Tuesday.
Clegg, a Liberal Democrat, aimed the attack at the anti-EU UK Independence Party (UKIP) and euro-skeptic factions of Prime Minister David Cameron's Conservatives two days before European elections, which are forecast to bring big losses for his pro-Europe party.
In an appeal to core liberal voters and others who are unimpressed by the anti-European Union rhetoric of the country's right-wing parties, Clegg will accuse skeptics of sacrificing Britain's historical ties to Europe for political gain.
"They are not thinking about Britain's interests," Clegg will say, according to extracts of his speech, to be delivered at the European Studies Centre at the University of Oxford. "They shroud their narrow nationalism in the language of patriotism. They mask their hostility towards Europe as British bulldog spirit.
"But these are false patriots. The isolation they offer is a breach of our history, of our great British tradition of engagement, and of our enlightened national self-interest."
Polls indicate the Liberal Democrats' share of the vote is set to fall. Senior party sources say the leadership is bracing itself for a rough ride after Thursday's European vote and local elections being held at the same time.
Several polls suggest UKIP's campaign for tougher rules on immigration and an immediate exit from the EU could give them first place when the European election results are announced on Sunday. Cameron's Conservatives are expected to come in third behind the center-left Labour party.
A separate survey on Britain's relationship with Europe released on Tuesday indicated that, amid the political debate about the EU, businesses were becoming less certain about Britain's future in the 28-country bloc.
The British Chambers of Commerce poll suggested that enthusiasm had fallen over the last year for Cameron's plan to renegotiate Britain's ties with the EU and hold an "in/out" referendum by 2017 if he wins a national election next year.
The number of firms who thought the strategy would be good for Britain fell by 10 percentage points to 54 percent and the number who were unsure of its impact rose to 19 percent from 11 percent.
Editing by Larry King