She is set to visit Northern Ireland, Scotland and Wales
The British Prime Minister Theresa May will visit Wales today as the government there tries to convince the devolved nations that their input will help shape its Brexit negotiations.
Mrs May has faced criticism from the Scottish Nationalist Party (SNP) that its compromise Brexit proposals were ignored, despite Number 10 launching the Joint Ministerial Committee as a forum to hear their concerns.
First Minister Nicola Sturgeon has used this as one of the key reasons for seeking a Section 30 order to organise a second independence referendum.
Ms Sturgeon said she is determined to hold the ballot and said Scotland would seek to remain part of the European Union.
"There is no queue to join the European Union and we have had several voices over recent times saying that if Scotland wanted to be in the EU then there would be a very open warm reception for that," she said.
But Mrs May has refused to agree to a second Scottish referendum before spring 2019, telling Ms Sturgeon "now is not the time".
Mrs May says she will not start discussions with the Scottish First Minister on her proposals to hold a second independence vote when she is about to begin Brexit negotiations.
She said it would "not be fair" to expect the Scottish people when they did not know what the future partnership with the UK would be or "what an independent Scotland would look like".
A spokesman for Mrs May said the trip to Swansea was part of an "ongoing engagement" with the nations, and that she will be "listening to people from right across the nation as we prepare to leave the EU".
The British government says it will trigger the Article 50 process, to begin the formal process of leaving the EU, before the end of the month.
This would then begin two years of formal talks to leave the union.
Wales - together with England - voted in favour of leaving the EU, while Scotland and Northern Ireland opted to remain.