The Conservative leader was speaking ahead of two crucial votes in the House of Commons that will determine if Johnson can fulfil his "do or die" promise to deliver Brexit at the end of next week.

Britain is entering a cliffhanger finale to a drama sparked by the 2016 referendum vote on whether to leave the EU, which has plunged the country into three years of political turmoil.

Johnson was forced on Saturday to ask EU leaders to postpone the deadline for leaving -- something he once said he would rather be "dead in a ditch" than do.

He was required by law to send a letter to the EU requesting an extension after MPs failed to back the divorce deal he struck with Brussels last week.

However, he still has a chance of avoiding a delay if he can get legislation implementing the treaty through parliament by October 31.

The Commons will hold its first vote on the bill at around 1800 GMT, followed by another vote on Johnson's timetable motion to rush it through parliament in just over a week.

Opening the debate, the Conservative leader urged lawmakers to support the legislation so "we can get Brexit done and move our country on".

He warned that if they failed, the "bill will have to be pulled" and he would seek an early election -- although he needs the support of the main opposition Labour party.

"I will argue at that election: let's get Brexit done," he said.

However Labour leader Jeremy Corbyn -- who has called for a second referendum on Brexit -- said Johnson was trying to "blindside" parliament into supporting a "rotten bill".

"A deal and a bill that fails to protect our rights and our natural world, fails to protect jobs and the economy, fails to protect every region and every nation in the UK," he said.

- EU 'will be ready' -

Johnson warned that voting against his timetable motion would kill any hope of leaving the EU with a deal next week, and risks a "no-deal" exit if the EU declines to approve a delay.

In Strasbourg, European Council President Donald Tusk said the other 27 EU leaders were mulling Johnson's request but it would depend on how MPs vote.

"It is obvious that the result of these consultations will very much depend on what the British parliament decides, or doesn't decide," he told the European Parliament.

"We should be ready for every scenario."

He added on Twitter: "I made clear to PM @BorisJohnson: a no-deal Brexit will never be our decision."

In Paris, French foreign minister Jean-Yves Le Drian said he saw "no justification at this stage" for further delay.

"We've been waiting for three years for this decision. It's important for it to be announced today, because otherwise there will no option except 'no deal,' which is not the solution we prefer," he said.

Businesses and markets on both sides of the Channel fear a "no-deal" Brexit, where Britain severs ties with its closest trading partner with no new plans in place after 46 years of integration.

Johnson said that if MPs backed his bill, he would immediately "de-escalate" preparations for no deal.

- More hurdles ahead -

But even if Johnson wins the two votes on Tuesday evening, MPs could still derail his bill.

Some lawmakers want to secure much closer future trade relations with the EU after Brexit, seeking to amend the bill to demand Britain stay in the bloc's customs union.

After tens of thousands of people demonstrated in London on Saturday for a second referendum, some MPs will also seek to attach plans for a "People's Vote" to the bill.

If the Brexit withdrawal bill passes the Commons unscathed, it must still be approved by the unelected upper House of Lords -- and then the European Parliament.

The deal is the second of its kind, after a Brexit text agreed by Johnson's predecessor Theresa May was rejected three times by MPs earlier this year.

It covers EU citizens' rights, Britain's financial settlements, a post-Brexit transition period until at least the end of 2020 and most controversially, new trade arrangements for Northern Ireland.