Theresa May's government accused of forcing through hundreds of pieces of Brexit-related legislation without proper parliamentary scrutiny.

Ministers have so far got over 100 pieces of secondary legislation relating to Brexit through Parliament.

However, there are well over 400 more statutory instruments left to pass with Brexit day just weeks away.

The government is using an array of tactics to force this legislation through Westminster without scrutiny, senior MPs tell Business Insider.

The Treasury is accused of refusing to publish impact assessments and dumping hundreds of pages worth of legislation on MPs who have just hours to assess them.

"Ministers are seeking to drive through delegated legislation that often they themselves do not fully comprehend" Shadow Chancellor John McDonnell tells Business Insider.

LONDON — Theresa May's government is trying to sneak through vast swathes of new legislation in the final weeks before Brexit without proper democratic checks, her opponents have warned.

Ministers are pushing hundreds of pieces of secondary legislation — known as statutory instruments (SIs) — through Parliament in the final weeks before the United Kingdom leaves the European Union on March 29.

SIs pass through parliamentary committees but do not always require full House of Commons approval. May's government has around 600 SIs relating to Brexit which it aims to get through Parliament before Brexit day on March 29.

However, just 117 SIs had completed their passage through Parliament at the time of writing, while up to 40% hadn't even been laid before Parliament to begin their journey through Westminster.

To speed up the process and ensure the UK is ready for a potential no-deal Brexit, ministers are using an array of tactics to limit the extent at which MPs can scrutinise SIs, shadow ministers and senior MPs have told Business Insider.

SIs are normally used only for minor, technical changes relating to primary legislation. However, the sheer scale of the SIs going through Parliament and the speed with which they are being passed, has led to fears that more impactful and controversial changes are being sneaked through.

"We have raised directly with government ministers and at each SI committee the way in which ministers are seeking to drive through delegated legislation that often they themselves do not fully comprehend and whose impacts has not been properly assessed," Shadow Chancellor John McDonnell told BI.

Shadow Chancellor John McDonnell. Simon Dawson / Reuters

On Monday Shadow Business Minister Bill Esterson told the House of Commons that he was alarmed about what he and others described as a growing trend of government ministers trying to avoid scrutiny.

He told BI this week: "Small committees are being used to bring in drastic changes using a process designed for mainly technical, non-controversial adjustments. Major changes to the statute book are being pushed through with minimal debate, in committees that are stacked in favour of the government."

The Labour MP added: "This lack of transparency and limited opportunity for scrutiny is deeply concerning and could have very serious implications."

The Treasury is accused of dumping multiple SIs on individual committees to look at in single sessions, leaving MPs with just hours to trail through hundreds of pages of technical details which in some cases took years to put together.

Ministers have also failed to publish impact assessments for certain SIs, like those on financial passporting after Brexit. This has forced MPs to form conclusions on SIs without seeing their predicted impact.

In some cases, ministers have published assessments just minutes before committees began assessing them.

"I am deeply concerned by the significant nature of the legislation passing through delegated legislation committees relating to financial services," Shadow Treasury Minister Anneliese Dodds told BI.

"This legislation is passing through regulatory procedures that were not designed for changes of this magnitude."

Dodds, the MP for Oxford East, added that she had sat on at least three committees where ministers had acknowledged that the legislation required impact assessments but failed to publish them prior to the sessions.

"The Conservatives expect us to pass legislation without information that they have themselves deemed necessary to produce. Trust in Government is contingent on transparency which this Government is failing to provide."

Other senior MPs told BI that some of the SIs put before committees recently are too important to be classed as secondary legislation, and ought to be put before the Commons as primary legislation for debates and votes.

There are concerns that the scale of this problem will only grow as the government runs out of time to get heaps of Brexit-related legislation through the House of Commons before the scheduled exit day of March 29.

Jo Stevens, supporter of the People's Vote campaign and member of the European Statutory Instruments Committee, told BI: "Brexit is clogging up the pipes of our democratic institutions, with mountains of legislation and statutory instruments being dumped on Parliament without much-needed time for proper scrutiny or transparency."

"The Government seems to have descended into attempting to impose their vision of Brexit by fiat, and they are failing to meet basic standards of transparency and accountability."

She added: "This is not acceptable for a country like ours with our proud democratic traditions."

The Treasury did not respond to BI's request for comment.