Former health minister Norman Lamb has said he will not enter the race to replace Tim Farron as Lib Dem leader.
Mr Lamb, who lost out to Mr Farron in 2015, told the Guardian his decision followed a “gruelling” election period.
He said the party’s anti-Brexit stance was “toxic” to many in his own seat and accepted his abstention on the Article 50 vote had angered many in the party.
Ex-business secretary Sir Vince Cable is running after Mr Farron announced his resignation after the election.
Mr Farron said he was standing down, having been “torn between living as a faithful Christian and serving as a political leader” during the election campaign – which saw him face questions about his views on gay sex.
Mr Farron beat Mr Lamb in the 2015 leadership contest with 56.5% of votes cast. Mr Lamb said on BBC One’s Question Time last week he was “thinking about” running again but he didn’t want to make a snap decision so soon after the election campaign.
In an article for the Guardian Mr Lamb said that while he had received support from party members and others to run again, he would not be putting himself forward.
He said the party’s position on Brexit – the Lib Dems favoured a second referendum on the final Brexit deal – had been “toxic to many erstwhile Liberal Democrat voters in North Norfolk”, Mr Lamb’s constituency in an area which voted to leave the EU in last year’s referendum.
“I found myself sympathising with those who felt that the party was not listening to them and was treating them with disdain.”
He also said his decision to abstain on the vote to trigger the formal process of leaving the EU had been “an act of betrayal” to many in the party.
“I have been accused of supporting a ‘hard Brexit’ – the very last thing I want – while a Lib Dem source told the Evening Standard this week that the abstention ‘looks like he can’t make a tough call’. It is actually quite tough to go against your party, and I did it on a matter of principle.”
Sir Vince, who returned to Parliament after two years when he won back his Twickenham seat at the general election, has said he will continue with the Lib Dems’ call for a fresh referendum on any Brexit deal.
Announcing his decision to run, the former cabinet minister, who has served as the party’s deputy leader and acting leader in the past, told Lib Dem Voice: “We must fight for the British public to have a final say on the government’s deal with a chance to stay in the EU if the deal is not good enough. To achieve this, we will need to work with like-minded people in other parties.”
The Lib Dems won 12 seats at the general election, four more than in 2015, but its vote share actually fell to 7.3%.
Jo Swinson, who had been the bookies’ favourite to win the race, ruled herself out to stand as deputy leader – and was elected unopposed.
Another former cabinet minister, Ed Davey, has not ruled out standing and has said he will make an announcement by the end of the week.