David Cameron today defended the deal he struck in Brussels last week and launched an angry attack on Boris Johnson's motives for backing Brexit.
The prime minister used a statement to the Commons to formally set out his case to MPs for a 'Remain' vote at the June 23 referendum.
And in what has been interpreted as a direct swipe at Boris, Cameron suggested others had picked a side based on ulterior motives.
"I am not standing for re-election. I have no other agenda than what is best for our country. I am standing here today telling you what I think," he told MPs.
"My responsibility as prime minister is to speak plainly about what I believe is right for our country. And that is what I will do every day for the next four months."
Boris has been accused of choosing to back Brexit as a political tactic designed to secure him the leadership of the Conservative Party once Cameron steps down before 2020.