LONDON (Reuters) - British Prime Minister Theresa May has less than eight months to negotiate a Brexit deal, sell it to her divided Conservative Party and win parliamentary approval.

Below are significant dates as Britain nears its departure from the European Union in March:

PARLIAMENT RETURNS - Sept. 4 to 13

Lawmakers return after spending the summer in their constituencies. Conservatives will have listened to party activists, some of whom feel May’s Brexit plan betrays promises made in the 2016 EU referendum campaign.

Her minority government must pass a mountain of legislation on everything from immigration to fisheries policy before Britain leaves the EU. During the previous parliamentary session, a number of pro- and anti-Brexit Conservatives rebelled, meaning May’s government had to survive several very close votes on trade and customs legislation in July.

EU LEADERS MEET - Sept. 20

May will discuss Brexit with the EU’s 27 other leaders at an informal summit in Austria. Having sent ministers across the bloc to sell her plan during the summer, the meeting will signal whether this has paid off, and if a deal is possible.

LABOUR CONFERENCE - Sept. 23 to 26

The opposition Labour Party could play a role in the type of Brexit Britain gets. If May cannot win round her party, she could look to Labour leader Jeremy Corbyn to help get her plan through parliament.

Corbyn’s team have said it does not meet their tests for what Brexit should look like. But his party is also divided and pro-EU members could press the leadership to soften their stance at Labour’s annual conference.

CONSERVATIVE CONFERENCE - Sept. 30 to Oct. 3

The Conservative Party often holds its annual conferences in a febrile atmosphere. Last year, May had a calamitous speech in which she lost her voice, was handed a resignation notice by a prankster, and the stage backdrop fell apart as she spoke.

This time tensions over her Brexit plan are likely to surface as rivals use the occasion to make their pitch to grassroots members.

May will sound out support for whatever agreement she aims to reach at an EU leaders’ meeting.

EUROPEAN COUNCIL - Oct. 18

May meets fellow EU leaders and the European Commission to try to seal deals on the terms of Britain’s withdrawal and what kind of relationship it has in the future.

This should cover trade and how to prevent a return of controls on the frontier between Northern Ireland and the Irish Republic, which will become Britain’s only land border with the EU. These are the main areas of disagreement which have all but stalled negotiations and caused May’s government to step up preparations for leaving without any deal.

Both sides are still working toward an October deadline, although it may be possible to extend that to December and still allow time for both sides to approve the deal. An EU Council meeting is also planned for Dec. 13-14.

PARLIAMENTARY VOTE ON BREXIT DEAL - Unscheduled

If May secures a deal, she has to get parliament to approve it. Her Conservatives hold 316 seats in the 650-seat lower house, and she relies on a Northern Irish party to win parliamentary votes.

To win approval, she must overcome differences between Conservatives who want a radical break with Brussels, and those who want closer ties. Otherwise, she may have to look to the opposition for support. Both paths are full of uncertainty.

Failure could trigger a move against her leadership of the Conservative Party, or the government’s collapse and an early election.

BREXIT - March 29, 2019 at 2300 GMT.