Jeremy Corbyn has insisted the fresh wave of defiance and latest frontbench resignation in his party over Brexit are "not a disaster".
The Labour leader also said rumours that he was preparing to quit the party's top job were "absolute nonsense".
During fractious exchanges on BBC Breakfast, Mr Corbyn accused the programme of reporting "fake news".
Clive Lewis quit as shadow business secretary to defy the three-line whip so he could oppose the European Union (Notification of Withdrawal) Bill.
He joined 51 of his Labour colleagues to vote against the Government while 13 did not vote.
Conservatives seized on Labour's turmoil over the vote to back the start of Britain's divorce talks with the European Union to claim the Opposition was "hopelessly divided".
Asked about the rebellion by Labour MPs, Mr Corbyn told the programme: "No, it's not a disaster."