While David Cameron has been in Brussels negotiating the terms of UK membership of the EU, there has been yet more infighting within Brexit party Ukip.
Douglas Carswell, Ukip's only MP, has once again challenged Nigel Farage's leadership of the party, telling BBC Essex that the party needs a "fresh face" as leader with "an optimistic message for the future", and that:
[Ukip] needs to change gear and to change its management if it's to go the next level.
The Clacton MP did not mention Farage by name, but said "no party is defined by any one person".
He has previously stated that he does not want to be party leader himself.
Farage responded to Carswell's comments by telling the BBC that Carswell should "put up or shut up".
The Clacton MP made the same call in the aftermath of May's general election, in which Farage's predicted 'Purple Revolution' of up to 40 Ukip parliamentary seats failed to materialise.
Carswell himself hung on to his seat in both a by-election in 2014 and this year's general election, having defected from the Conservative party in August 2014.
(Picture: Peter Macdiarmid/Getty Images)