Image copyright Getty Images Image caption The result of the Labour leadership election will be announced on Saturday

Jeremy Corbyn will put Labour on a general election footing if he is re-elected leader, Newsnight has learned.

Mr Corbyn is planning to tell the party that Theresa May could call an election as early as next spring to secure a mandate for her Brexit negotiations.

The leader hopes the prospect of an early poll might instil some discipline among Labour MPs, and he would help bring it about.

Newsnight understands he would instruct his MPs to vote for an early election.

Restore authority

Under the Fixed-term Parliaments Act, an early election has to be supported by at least two-thirds of MPs.

Mr Corbyn is officially waiting for every vote to be counted in the Labour leadership election before declaring victory, but he is already turning his mind to early steps he will take to restore his authority.

Placing the Labour Party on an election footing would, in his mind, be a tactically wise move to help encourage discipline in the Parliamentary Labour Party (PLP).

But Mr Corbyn also believes that Labour should focus on an early general election in a laser-like way because he believes the prime minister has ruled out a snap election but is keeping her options open beyond the end of this year.

Mrs May said earlier this month that an election should not be held before 2020.

Newsnight understands that Mr Corbyn is expected to outline practical steps to show his preparations for an election.

This will involve putting policy making, the party organisation and campaigning on an election footing.

Shadow cabinet

Former Liberal Democrat leader Lord Ashdown told Newsnight that the prime minister may be forced to call an early general election if she opts for a Brexit deal which alarms Eurosceptics.

Lord Ashdown said: "If she chooses - as I think she will - something that's in the best interests of Britain if it has to be Brexit, ie continued access to the single market, she has 100 MPs who are going to say 'up with this we will not put'.

"She then loses her majority in the House of Commons. Sooner or later she has to bring that back to the House; she will find herself in that conundrum.

"Labour will say no for opportunistic reasons, they won't support her. If she wants to get that through she can only go to the country.

"So she doesn't think she wants an election, at least I don't think she does, I think she's honest in saying she won't get one.

"But I'm not sure that the civil war in the Tory party not yet visible, but will become increasingly visible as she identifies that will make that the only way she can get to a solution."

Media playback is unsupported on your device Media caption Lord Ashdown believes the prime minister may put her Brexit deal to the electorate

Mr Corbyn's planned announcement comes as the Labour leader seeks to woo former members of the shadow cabinet back into the fold in what is being dubbed an outreach programme.

Two former members of the shadow cabinet have indicated to Newsnight they would be prepared to return if invited by Mr Corbyn.

Nia Griffith, the former shadow Wales secretary, said that Labour MPs should be as positive as they can be if Mr Corbyn wins.

Another former shadow cabinet member, who was highly critical of Mr Corbyn when they resigned in the summer, says it will be time to pull together if he wins.

Membership increase

A much larger group would, as The World This Weekend reported on Sunday, only return to the frontbench if elections to the shadow cabinet are restored.

Tom Watson, Labour's deputy leader, will call on the party's National Executive Committee (NEC) on Tuesday to support shadow cabinet elections in time for a vote at next week's Labour Party conference.

The PLP recently voted in favour of the restoration of these elections which were abolished by Ed Miliband in 2011.

Newsnight, which understands that Mr Watson is not confident the PLP proposal will be accepted by the NEC, believes Mr Corbyn will call on the NEC to take its time to consider alternative plans to give Labour Party members a greater say.

This could involve allowing members to elect a proportion of the shadow cabinet and increasing the representation of members on the NEC to take account of the rapid increase in Labour members since Mr Corbyn's election last year.

The Labour leader believes there should be a broader consultation on widening democratic participation at all levels of the party which should not be concluded at Tuesday's NEC meeting.

Mr Corbyn believes the consultation should be completed rapidly though he believes it would be wrong to rush ahead at the NEC meeting.

A delay until after next week's party conference would mean that his proposal would be decided by the new NEC whose members are more supportive of Mr Corbyn.