Norman Lamb did offer to resign as Nick Clegg's chief aide because of his concerns over the government's NHS reforms, he has revealed.

The admission by the North Norfolk MP follows the political storm that blew up earlier this month after he said on the Politics Show that if the reforms proposed by health secretary Andrew Lansley were not modified, he would find it 'impossible' to continue as the deputy prime minister's principal parliamentary adviser.

He has now said that he offered to resign before going on the show, so that he could speak freely on the issue of NHS reforms.

The disclosure came in an interview on London's LBC radio conducted by EDP columnist Iain Dale who tried to win his seat for the Tories in 2005.

'I offered to resign. I said that if it was easier to raise my concerns openly without embarrassment, I would do that. But I don't want to hold a gun to anyone's head,' said Mr Lamb.

Mr Dale then asked him: 'So you did offer to resign. So Nick Clegg knew that you were going to do that when you went on the Politics Show?' - on BBC TV on April 10.

Mr Lamb replied: 'Sure. I told Nick of my concerns. I raised it with him beforehand, and I did nothing behind anyone's back. But I felt that it was right to offer to resign, but that wasn't taken up.'

Mr Lamb's comments on the Politics Show on April 10 were immediately widely interpreted as a threat to resign. But Mr Lamb denied it when asked by the EDP later on the same day. 'I am not threatening to quit at all. I want to help the government get to a position in which the bill can proceed,' he said.

Last night Mr Lamb told the EDP that there is 'absolutely no conflict at all' between what he had said to Mr Dale and what he had said to the EDP on April 10. 'There is a big difference between threatening to resign and offering to. It was an offer to Nick which he did not take up. I was prepared to offer my position in government to make my case.'

On the Politics Show, he continued, he had been asked about what he might do if the NHS reform programme resulted in 'something untenable', and said that 'any principled person would have reached that view'.

Mr Lamb said that his sole objective is to get the reforms right, and that 'the principle of empowering GPs to take more responsibility, to be responsible for the money they are spending, is absolutely right'.

'But my concern is a sort of big bang, doing it too quickly by conscription from the centre' he continued. 'It's really important that we have a debate in an open and mature way at this stage so that we get the reforms right.'