By Mark Davies BBC News Online political reporter

Hain is UK Government's representative on the convention

After spending the last few weeks taking every opportunity to set out the government's position on the convention discussing Europe's future - and appearing to relish the challenge - he goofed badly on Tuesday.

The Wales secretary, always a willing interviewee anyway, can hardly be accused of shunning TV and radio in his efforts to defend the convention and Britain's stance on it.

From early morning radio shows to the Sunday political programmes, it seems Mr Hain rarely turns down an interview request.

His blunt rejections of calls for a referendum on the convention have made plenty of headlines, not least those on the front pages accusing him of arrogance.

The convention is a "tidying up exercise", he has said. That won headlines. So did his appeal to those campaigning for a poll to "put away their placards".

It was a simple enough mistake - but a bad one for a minister to make

Mr Hain will have been happy with those. He won't be happy, however, when he looks at Wednesday's newspapers.

"Hain in trouble over EU blunder," said one. "Hain referendum gaffe rocks Blair," said another. There was more of the same pretty much everywhere you looked.

Happy

It was a simple enough mistake - but a bad one for a minister to make.

Asked again about a referendum, he suggested that people could vote against the government in next year's European elections if they felt unhappy about the approach to the convention.

His exact words, indeed, were: "I would be quite happy to fight the next European elections on a Labour platform endorsing this treaty, and the Conservatives can oppose it, and then the people will decide."

Cue Tory claims that what he was saying was that Euro elections would be a referendum on the convention.

Absurd, said Mr Hain. Not true, said Downing Street. All he was saying, they argued, was that voters would have a chance to deliver their verdict on the government's policies in the usual way - via the ballot box.

But by then it was too late. It was a blunder and the Wales secretary had given his opponents a clear shot on goal. And they didn't miss the opportunity.

Licence

Mr Hain said he was "depressed" by Tory spokesman Michael Ancram's response to the comments - it was a case of "deliberate misinterpretation", he claimed.

What he didn't add, of course, was that if he had been in Mr Ancram's shoes, he would have done exactly the same thing.

Mr Hain is by no means a stranger to dropping the odd gaffe here and there. Highly ambitious, he is regularly written up as a government maverick who can usually be relied upon to say something controversial.

In the past he has got himself into trouble over the euro. A fervent advocate of UK membership of the currency, his pro-euro declarations have regularly popped up in the papers.

Downing Street has never appeared particularly concerned, with the suggestion being that more often than not, Mr Hain simply says what the prime minister would like to if he could.

In other words, the Wales secretary has been given a licence to speak by the prime minister. Which is a good job, because Mr Hain is never short of a word or two.

In this case, however, there was clearly irritation in Downing Street about Mr Hain's slip-up.

Fruitful

The government has appeared slightly wrong-footed over the furore caused by the plans for the EU's future. For months the convention has been hammering out the proposals which appeared this week - so there was plenty of time to prepare.

Mr Hain's job since the Tories began what has become a fruitful onslaught on the plans has been to explain why the government opposes a referendum and to cast the Conservatives as xenophobes who want to withdraw from the EU.

He has done that forcefully and until Tuesday, fairly effectively.

Mr Hain has, of course, sat on the convention debating the finer points of the structure of the European Union for the last 15 months.

When you've been through something like that, it's probably time to get a few things off your chest.

But perhaps Tuesday's appearance on the Today programme was just an interview too far.