British politicians from across the spectrum have "all gone crazy" over Europe and created a poisonous debate which has destabilised successive governments, Nick Clegg claims today.

In a passionate intervention in the debate on the new Lisbon treaty, which is undergoing lengthy parliamentary scrutiny, the pro-European Liberal Democrat leader says it is time to stage a referendum on whether Britain should stay in the EU.

Writing in today's Guardian, Clegg says: "We've all gone crazy. Pro and anti, Europhile and Eurosceptic, trading blows about the Lisbon treaty in grand rhetoric that obscures the facts. If you're pro-European, like I am, you're accused of being a sell-out. If you're anti-European, like most of the Conservative party, you're accused of being a headbanger."

Clegg says it is time to give the country its first chance in 33 years to decide if it wants to be in or out of the EU. "Nobody in this country under the age of 51 has ever been asked that simple question. That includes half of all MPs. We've been signed up to Europe by default: two generations who have never had their say."

Clegg, 41, a former MEP of Dutch and Russian heritage who made his name as a senior official in the European commission, will this week table an amendment in parliament to the Lisbon treaty bill demanding an "in or out" referendum. This will not succeed because Labour and the Tories do not want such a poll. Labour believes no referendum is necessary, while the Tories are waiting for next week, when MPs will vote on whether to have a referendum on the narrower issue of the Lisbon treaty. This is also unlikely to succeed.