LONDON — Former British prime minister Tony Blair is pressing his long-held view that voters should be given a chance to rethink Brexit once plans for Britain’s departure from the European Union are clear.

Blair said Thursday that the Labor Party he led for 13 years should be actively challenging Brexit rather than going along with plans laid out by Prime Minister Theresa May and her Conservative Party allies.

May’s government is negotiating exit plans and the outlines of a new trade relationship with the EU with an eye toward departing the bloc by a March 2019 deadline.

Blair and other foes argue that voters should be able to review these terms and decide whether to go ahead rather than be bound by the 2016 referendum, which saw Britons back Brexit by 4 percentage points.

‘‘I’m simply saying one very, very simple thing, which is that in 2016 you knew you wanted to get out of the European Union but you didn’t see the terms of the alternative relationship,’’ Blair told the BBC radio. ‘‘If when you see those terms you think it is better to stick with Europe you are entitled to have that say.’’

Blair said Labor leader Jeremy Corbyn’s pro-Brexit strategy is misguided, and that he should instead be branding the withdrawal from the EU as ‘‘the Tory Brexit’’ to capitalize on growing public doubts about the process, caused in part by Britain’s slowing economic growth.