Theresa May's grand plan to deliver Brexit could be a lot more complicated than people think
May, along with Secretary of State for Exiting the European Union David Davis, will announce plans to introduce the bill when they address the Conservative Party conference on Sunday.
If passed, the bill will turn all EU law which currently affects Britain into British law once Brexit has officially taken place. These laws can then be altered or abolished by Parliament.
"It's very simple. The moment we leave Britain must be back in control," Davis will say at the Birmingham conference, which Business Insider UK is attending. "And that means EU law must cease to apply."
"People voted for power and authority residing once again with the sovereign institutions of our own country."
May will introduce the Great Repeal Bill before the end of the year and work with both houses of Parliament to get it implemented prior to triggering Article 50 before the end of March 2017.
It will replace the 1972 European Communities Act, which for decades has made EU law supreme over British's own.
The announcement is the first real clue we've been given on how the prime minister intends to deliver a Brexit after weeks of recycling the phrase "Brexit means Brexit."
However, getting the legislation passed won't be easy.
MPs will get the opportunity to vote on it - in theory, they could refuse to support it until certain amendments are made, or, in less likely but not impossible scenario, block it all together.
The prime minister may also have to persuade the national governments of Scotland and Northern Ireland to agree to the legislation. EU law is deeply entrenched into the devolved status of these countries, meaning May might have receive consent from Edinburgh and Belfast.
Both Scotland and Northern Ireland voted to Remain in the June referendum. In Scotland, 62% of voters wanted Britain to stay in the 28-nation bloc.
The Great Repeal Bill doesn't really reveal anything about what May and her government wants post-Brexit Britain to look like. The issue of whether the country retains access to the single market remains to be seen.
Liam Fox, the International Trade secretary, hinted this week that Britain would leave the single market, allowing government to end the free movement of people and enforce its own border controls.
Both EU Commission President Jean Claude-Juncker and EU Parliament Brexit negotiator Guy Verhofstadt have stated Britain will not be able to retain single market access if it decides against continuing the free movement of people.