The Prime Minister said she wanted to "strengthen Wales and Britain to unify Wales and Britain" as she prepares to go to Brexit for a year.
Theresa May Visits Great Britain on Thursday Vale of Glamorgan (1
But Wales & # 39; First Minister Carwyn Jones warned that her Brexit plan "would have serious consequences for our economy."
The Welsh Government supports the UK, which remains in the EU's Single Market and Customs Union, which means that Member States together apply the same import taxes on goods from outside the Union In a speech in March, Ms. May reiterated her plan to leave both the Internal Market and the Customs Union when she called for a free trade agreement for most sectors of the economy.
She warned that "no one will get what they want" From the Brexit negotiations to get Mr. Jones to criticize the speech for "having too many vague wishes and terse details".
At that time, the first minister said that the prime minister had not "spelled out" how she wanted to achieve "smooth" trade with the EU "outside a customs union".
In his recent statement, Jones said that the United Kingdom would leave the EU on March 29, 2019 at 11:00 pm BST. "People in Wales still have no idea about what happened after the Brexit agreement that the Prime Minister wanted with Brussels"
He added: "The clock is ticking, companies and the public sector need to be able to do this Planning change but the lack of clarity on the part of the UK government makes this nearly impossible.
"I do not question Brexit – the UK is leaving the EU. But we deserve to know what the plan is.
"We will continue to fight for a sensible Brexit that protects Wales' economy and jobs."
& # 39; Historical Nations & # 39;
Ms. May will visit all four UK countries on Thursday, including Ayrshire in Scotland, Newcastle, Belfast, Barry at Vale of Glamorgan before finishing in West London.
In the run-up to the visits, the Prime Minister said: "I am determined that we will strengthen the EU in the years to come, unifying our bonds, because ours is the most successful union in the world."
"The United Kingdom contains four proud and historic nations, but together we are so much more than the sum of our parts and our Union is a tremendous force for good
Regarding a continuing dispute with the Welsh Government over what the ministers in Cardiff considered The Prime Minister said: "Each of the decentralized nations will increase their decision-making powers." Brexit
"Do not make mistakes, this government is absolute. We are fully committed to deconcentration, as we have in recent years with groundbreaking pieces of legislation, "she said.
"But as Prime Minister of the United Kingdom, I have the absolute responsibility to protect the integrity of the United Kingdom as a whole."
"This means ensuring that no new barriers are created in our common internal market and that Britain is capable is to fulfill its international obligations in the future.
"No Prime Minister could leave these things to chance because they are. This is crucial to our success as a country in the future."
Last week members of the Cardiff Bay Assembly passed a law known as the Continuity Bill, as an insurance policy against the UK government's so-called Withdrawal Act.
Plaid Cymrus Brexit spokesman Steffan Lewis said: "Our own parliament, the National Assembly, has made it very clear that we, with the support of every party there, will use laws to protect us from Westminster's seizure of power.
" The Continuity Bill will simply ensure that all powers in decentralized areas are transferred after Brexit.
"Theresa May must use her visit to Wales to assure our citizens that the Continuity Bill will be respected and that Westminster will not challenge it in court."
"If the Prime Minister believes there is none such power takeover in the first place, it should have no concerns about legislation that retains our existing powers. "