The British government will set out in the coming week how it plans to shape its relationship with the European Union upon leaving the bloc, Prime Minister Theresa May says.
Since taking office in July, May and her Brexit minister David Davis have given little detail about what Britain's future relationship with the EU will look like, saying only they want it to involve curbs on immigration and a good deal on trade.
"He (Davis) will be making a statement to parliament this week about the work that the government has been doing over the summer and obviously how we are going to take that forward in shaping the sort of relationship we want with the EU," May told the BBC in an interview recorded before she left Britain for the G20 summit in China.
On her way to the summit, May told reporters Britain's economy will suffer as a result of the decision to leave the EU despite signs in recent economic data that the impact has not been as severe as some predicted.
May told the BBC she would use the summit to begin talks with world leaders including US President Barack Obama, Indian Prime Minister Narendra Modi and Australian Prime Minister Malcolm Turnbull over future trade deals.
"I want to talk about how we can scope out what a trade deal and the negotiations on a trade deal would be like so that when the time comes, when we are able to sign those deals, we are able to do so," she said.
May, who upset Chinese officials by delaying a $US24 billion ($A32 billion) project to build a partly Chinese-funded nuclear power plant, is also due to hold a one-to-one with Chinese President Xi Jinping at the summit. She told the BBC she would be making a decision on the deal later this month.
May has been clear she will not trigger Article 50, the formal process of leaving the EU, this year in order to give Britain time to prepare for upcoming negotiations, but said it would not be "kicked into the long grass".
May also said there would be no early national election, despite some in her ruling Conservatives believing turmoil in the opposition Labour Party gives them an opportunity to increase their small parliamentary majority.
