Liberal Democrat MP Norman Lamb has said he is considering quitting the party over its position on Brexit.

The former minister warned that his party risked becoming a "mirror image" of the European Research Group (ERG) of hardline Tory Eurosceptics, suggesting it was "stuck in a trench not moving".

Admitting he was thinking of resigning the Liberal Democrat whip, the MP said he found the current situation "really distressing" and criticised colleagues who "just adopt a position and will not budge from it".

Mr Lamb broke with his party during Monday's "indicative votes" on Brexit to back plans for a softer exit involving either a customs union with the EU or staying in the single market, while the party line was to reject all options apart from a fresh referendum and revoking Article 50.

He was the only Liberal Democrat MP to vote for the single market plan, while only he and former party leader Tim Farron backed the customs union proposal.

The admission that he could leave his party comes a day after moderate Conservative MP Nick Boles announced he was quitting the Tories, saying the party "refuses to compromise".

Mr Lamb told BBC Radio 5Live that he had a "really, really difficult decision" to make, saying: "I've been terribly proud to represent this party in our national parliament for 18 years now but it didn't feel yesterday like the party I know and have loved.

"I've got some big decisions ahead of me but this is really distressing and difficult. I really struggle with people who just adopt a position and will not budge from it.

"It's not the sort of politics that I favour - I favour trying to find common ground. As a liberal I believe in pluralism - different views coming together, trying to find compromise to work your way through it.

"That's what we do in every workplace around the country - surely we should be doing it in our national parliament in the national interest."

In comments that will be seen as a stinging attack on Sir Vince Cable's leadership of the party, Mr Lamb said the Liberal Democrats were at risk of becoming a left-wing equivalent of hardline Conservative Brexiteers in the ERG.

The front pages on what would have been Brexit Day Show all 12 1 /12 The front pages on what would have been Brexit Day The front pages on what would have been Brexit Day March 29 2019 - The original date for Britain's departure from the EU, what do the newspapers have to say about it? The front pages on what would have been Brexit Day Daily Express The Daily Express focuses on the fact that today was the original day for Britain's departure from the EU The front pages on what would have been Brexit Day Daily Mail The Daily Mail warns MPs that they have "one last chance" to back the Prime Minister's Brexit deal The front pages on what would have been Brexit Day The Independent The Independent Daily Edition reports that the Prime Minister is gambling as she holds a vote today on the withdrawal agreement The front pages on what would have been Brexit Day The Sun The Sun reports that the Prime Minister last night sought to convince DUP leader Arlene Foster to back her deal The front pages on what would have been Brexit Day The Guardian The Guardian reports that some ministers want the Prime Minister to step down now, while Michael Gove becomes the favourite at the bookies to replace her The front pages on what would have been Brexit Day The i The i reports that Boris Johnson is preparing his leadership bid for when the Prime Minister resigns The front pages on what would have been Brexit Day The Times The Times reports that Brexit may be delayed for a further year The front pages on what would have been Brexit Day The Daily Telegraph The Daily Telegraph reports that the Prime Minister is making a "desperate final plea" to pass her Brexit deal through the house of commons The front pages on what would have been Brexit Day Financial Times The Financial Times reports on the Brexit Betrayal march that will reach London today after setting off from Sunderland with the intention of reaching London on Brexit day The front pages on what would have been Brexit Day Daily Mirror The Daily Mirror reports on the Prime Minister's difficulty passing her deal through the commons The front pages on what would have been Brexit Day Daily Star The Daily Star calls on its readers to shut up about Brexit

He said: "I don't want us to be the mirror image of the ERG, just stuck in a trench not moving, and that's why I felt particularly distressed yesterday.

"The bottom line is I'm a liberal and I'm that to my core. My judgement is whether I need to resign from the whip of this group but remain a Liberal Democrat."

Mr Lamb said he fully supported local Liberal Democrat activists but felt "a sense of dislocation between me and the centre of gravity in Westminster now".

EU chief Brexit negotiator Michel Barnier says he sees 'three possible situations'

However, he said he had not made a final decision about whether to leave the party and would be holding talks with Liberal Democrat chief whip Alistair Carmichael.

He also appeared to rule out joining The Independent Group, saying he was more likely to sit as an "independent Liberal Democrat".

MPs rejected all four Brexit proposals in front of them during Monday's votes, leaving Britain's departure from the EU in chaos.