Jeremy Corbyn will pledge to resolve the issue of Brexit in six months if elected at the upcoming General Election.
The Labour leader is giving a speech in Harlow on the morning of Tuesday, 5 November.
It will be focussed on the party's Brexit policy, which includes negotiating a new agreement with the EU and then holding a referendum.
The 70-year-old will say: "An incoming Labour government will first secure a sensible deal.
"That will take no longer than three months because the deal will be based on terms we’ve already discussed with the EU, including a new customs union, a close single market relationship and guarantees of rights and protections.
"So if you want to leave the EU without trashing our economy or selling out our NHS you’ll be able to vote for it. If you want to remain in the EU, you’ll be able to vote for that.
"Either way, only a Labour government will put the final decision in your hands."
Mr Corbyn will also accuse the Conservatives' Brexit deal of leading to a creeping privatisation of the NHS.
But Boris Johnson has denied that sections of the health service will be included in any post-Brexit trade deal with the USA.
The Conservatives say that if they win December's election they will implement their Brexit deal as soon as possible.
In a video posted on Twitter, the Prime Minister said: "We've got a great deal ready to go oven-ready. Slam it in the microwave and it's done.
"We can come out by the end of January at the very latest."
The Liberal Democrats, led by Jo Swinson, have been consistently opposed to any form of Brexit.
They have called for a second referendum and say they will campaign to remain in the EU.
The Brexit Party, meanwhile, have also reject Boris Johnson's deal. They claim it does not deliver the result of the referendum, and are calling for a 'clean-break Brexit'.