The UK cannot afford to "squander" more time deciding whether and how to leave the EU, Boris Johnson will say in his first major speech of the election.
He will argue that ending the current "groundhoggery" will deliver a big economic boost and enable the UK to focus on other priorities.
But former Tory David Gauke said Mr Johnson's plan will lead to a "bad outcome for the country".
Labour said the PM's deal is flawed and has promised another referendum.
Jeremy Corbyn has said he would negotiate a better deal on the terms of the UK's exit and give the public the choice of whether to accept it or remain in the EU in a public vote next summer.