Prime Minister Theresa May will publish her plans for a post-Brexit legal shakeup next week, just one day after formally launching negotiations.
May is expected to trigger Article 50 in the middle of next week, and she will launch an immediate follow up with the publication of a white paper on her Great Repeal Bill on Thursday.
The white paper will lay out how the government plans to convert the "acquis communautaire" of European law's and obligations into British statutes in the aftermath of Brexit.
The Bill, first announced at last year's Conservative party conference, will replace the European Communities Act, and is expected to be introduced in the Queen's Speech at the opening of parliament in May.
The UK's ambassador to Brussels, Sir Tim Barrow, will deliver the Article 50 letter on Wednesday to launch a two year period of talks with the EU and member states, just over nine months after British citizens voted to quit the European Union.
European Council president Donald Tusk has said he will call a special summit of EU members in late April after receiving May's notification.
Negotiations can only be extended with the consent of the UK and all 27 remaining member states.
Separately, The Sunday Times reports that ministers in the Brexit department last week put forward plans to maintain support on offer to EU citizens currently living in the UK.
The plans would allow those already in the UK to continue claiming benefits to send home to families outside of the country, with any European nationals arriving after Wednesday not allowed the same entitlements.
Any offer is likely to be closely linked to the residency rights of Europeans currently living in the UK, and those of Britons currently on the continent.
A spokesman for the department said: "We have said we want to secure the rights of EU nationals already in the UK, and UK nationals in the EU.
"But no decisions of the kind speculated about here have been taken. We are clear that when the UK leaves the EU, it will make its own decisions about immigration."