Mr Kennedy, speaking to the first formal meeting of the Britain in Europe campaign, said he was unequivocally committed to Europe.

He pledged his party would campaign in favour of Britain joining the single currency.

Lib Dems will take fresh approach to euro

Mr Kennedy said: "I am sick to death of the sceptics trying to claim a monopoly on patriotism in the politics of this country.

"True patriotism today in British politics is pro-Europeanism.

"I'm not going to trim, I'm not going to equivocate, I'm not going to compromise on the European issue - period."

Mr Kennedy said his party would approach the issue in a bold, fresh and original manner.

He continued: "We are certainly up to the cause, we favour the cause and we will be arguing it vigorously and rigorously until the day that we get the referendum and win that referendum - let's go for it."

Lord Owen: "Over there"

Mr Kennedy criticised some of the senior figures of the Eurosceptic movement, including Lady Thatcher.

Their scepticism would only help those in favour of a single European currency, he said, adding: "They will also have David Owen over there, which will help as well."

Mr Kennedy said he would rather see a later referendum that that pro-Euro groups could win rather than an early one which they risked losing.