Brexit minister David Davis is to set out more detail on the Government's plans for the UK's withdrawal from the European Union in a statement in parliament on Monday, amid growing international unease over how it will pan out.
The government has given little away about its plans for Brexit since the June 23 vote, instead focusing on preparing for formal negotiations which it has said will not get underway before the end of the year.
In a statement ahead of his address to parliament, the Secretary of State for Exiting the European Union said: "This is an historic and positive moment for our nation.
"Brexit isn't about making the best of a bad job. It is about seizing the huge and exciting opportunities that will flow from a new place for Britain in the world.
"There will be new freedoms, new opportunities, new horizons for this great country."
Leaders in the EU and around the world are keen for Britain to begin the talks to end uncertainty that has hurt investment.
In a series of developments over the weekend at the G20 summit in China:
- Japan's government issued a stark warning about the impact of Brexit on Japanese firms in the UK;
- President Obama said the trading relationship between the UK and the US could become stronger in future but warned that a trade deal with the UK was not top priority;
- Theresa May ruled out an Australian-style points-based immigration system, saying there is "no silver bullet" to tackling the issue.
Last week Mrs May gathered her cabinet team for the first time since the summer break to discuss options for Britain's future ties with the single market post Brexit.
Following that meeting, the government said it would seek a unique rather than "off-the-shelf" relationship with the EU, involving controls on immigration as well as a good deal for those who trade in goods and services.
During a trip to Northern Ireland on Thursday, Mr Davis said Britain would ideally have tariff-free access to the EU's single market.