Next year’s Queen’s speech is being ditched by the government to ease the way in parliament for new Brexit laws.

In a highly unusual move, the parliamentary session is being doubled to two years. The leader of the Commons, Andrea Leadsom, said this would give MPs and peers the maximum time possible to scrutinise legislation taking the UK out of the European Union. It means the government will not put forward a new legislative programme next year.

The Conservatives delayed this year’s Queen’s speech as the party held discussions with the DUP to thrash out an agreement on propping up the minority government. A formal deal has yet to be secured but Tory sources have said there is a “broad agreement” on the principles of the speech, and state opening will now take place on Wednesday 21 June – two days later than originally scheduled.

Under the coalition government the event, which is traditionally surrounded by great pomp and ceremony, was dropped in 2011, with ministers insisting it would give parliament more time to scrutinise the government’s heavy legislative agenda. Labour at the time accused the coalition of an “abuse of power” and said it was aimed solely at easing the passage of controversial legislation. Extending the new session will allow MPs and peers to examine Brexit laws as well as domestic reforms in depth, according to the government.

Leadsom said: “While our top priority right now is supporting the victims of the terrible tragedy at Grenfell Tower, we also need to look ahead by setting out a legislative programme that not only delivers a successful EU exit but also a domestic agenda which aims to tackle the social injustices in our country. The UK will spend the next two years preparing for our departure from the European Union in a way that best places us to realise the opportunities ahead and build a fairer society. This will require substantial amounts of legislation, beginning with the great repeal bill.

“We will build the broadest possible consensus for our Brexit plans, and that means giving parliament the maximum amount of time to scrutinise these bills by holding a two-year session of parliament. It will mean we can work together to deliver a successful Brexit deal and a strong social legislative programme that delivers justice and opportunity to everyone.”

The government said the great repeal bill, which converts EU laws into British legislation, will be considered alongside other Brexit legislation.

No 10 said the government would deliver Brexit while also addressing deep-rooted inequalities in society.