- The Labor main opposition leader said once in power, he would seek to delay Britain's October 31 exit date from the European Union and then call a general election.
Corbyn -- the only person who can trigger a vote of no confidence in Prime Minister Johnson's government -- will do so after MPs return to parliament on September 3, if he feels sure of victory.
Conservative PM Johnson has pledged to take Britain out of the EU on October 31, without a divorce deal if one cannot be agreed with Brussels.
With time running out, MPs opposed to Brexit, or at least to a no-deal departure, are scrambling for viable plans to stop Johnson in his tracks.
In a letter to other opposition leaders and leading rebel Conservatives, Corbyn said his plan "can halt the serious threat of no deal, end the uncertainty and disarray, and allow the public to decide the best way ahead".
While the Scottish Nationalists, the second-biggest opposition party in parliament, welcomed the idea, the Liberal Democrats, the next-biggest, dismissed it as "nonsense", saying Corbyn could not lead the charge.
Corbyn has pursued so-called "constructive ambiguity" over Brexit -- and many of his own Labor MPs are queasy at the idea of the veteran leftist becoming prime minister.
Rebel Conservatives said they were happy to discuss the idea with Corbyn, Sky News television reported, while Greens and Welsh nationalists offered conditional support.