THE UK Government faces having to pass as many as 15 Brexit-related laws over the next few years, leaving “very little space” for other legislation, a report has warned.

The Institute for Government (IfG) said the average Queen’s Speech has just 20 new bills, meaning ministers will have to “ruthlessly prioritise” what they want to get through the House of Commons.

Along with the proposed Great Repeal Bill, the Government faces a “huge burden” of legislation on areas such as the UK’s post-Brexit immigration and customs systems. As relations between the UK and Scottish Government deteriorate, the IfG also warned SNP MPs could obstruct the Conservatives from passing measures if they are able to team up with Labour and rebellious Tory backbenchers.

“The legislation required for Brexit will leave little parliamentary time for anything else – and making a success of it will require a large volume of bills and secondary legislation to be passed by Parliament against a hard deadline,” said the think-tank’s head of research Hannah White.

“It will be a challenge for both the government and Parliament to do all this while still ensuring full scrutiny and leaving room for the government’s domestic policy agenda.”

The IfG – an independent charity that aims to increase government effectiveness – also warned the heavy workload of bills would mean ministers having to achieve a fine balance between giving too little and too much scrutiny of Brexit-related legislation.

It also argued that “a lack of clarity” about the role the devolved legislatures will play in legislating for Brexit could pose a problem.

“In the first session after the 2015 election the government passed 23 bills,” White told BBC Radio 4’s Today. “So that’s roughly the capacity that there is in government to draft these bills and in Parliament, in terms of parliamentary time, to pass them.”

The reality, she suggested, was that the government’s domestic priorities would “take a hit in the next couple of sessions”.

“The legislation required for Brexit will leave little parliamentary time for anything else”, she said.

A UK Government spokesman said it had made clear there would be additional legislation, in areas such as customs and immigration, on top of the Great Repeal Bill but insisted this could be completed within the parliamentary timetable.