Four Welsh Assembly members, including former Ukip MP Mark Reckless, have joined the Brexit Party.
Nigel Farage met with Mr Reckless, David Rowlands, Mandy Jones and Caroline Jones on a visit to the Senedd on Wednesday.
The politicians were all originally elected as Ukip AMs, although only Mr Rowlands was still in the party.
All four wrote to Elin Jones, presiding officer of the Welsh Assembly, asking to be formally recognised as a group.
A Brexit Party spokesman said the move followed a meeting last month between the four and Mr Farage at a rally in Newport.
"We are delighted that the group has come together to prosecute the result of the referendum in which the people of Wales made clear they wished to leave the EU," he said.
Mr Reckless, who will lead the new group, was previously a Tory MP who defected to Ukip in 2014.
He was elected to the Welsh Assembly, where he represents South Wales East, in 2016.
He tweeted: "I have decided to leave the Conservative Group in the Welsh Assembly as the UK Conservative government has broken its promise to deliver Brexit".
Mr Farage visited the Welsh town of Merthyr Tydfil on Wednesday afternoon, ahead of a rally in the car park of Trago Mills.
He spoke to traders in a vape shop and a beauty parlour on the high street.
When asked what would happen to European investment in the town after Brexit, Mr Farage answered: "Whose money?"
"Their money - does it grow on trees? We are massive net payers into this thing."
During the walkabout, one man shouted "shame" at Mr Farage, while another told him "You're not welcome in Merthyr".
In a statement, presiding officer Elin Jones said: "I wish to inform the Assembly that I have received a letter from four Members informing me of their wish to form a group in accordance with Standing Order 1.3.
"I am considering the matter in accordance with my duties under Standing Orders. I shall notify the Assembly of my conclusions in due course."
Plaid Cymru said the Brexit Party had "no democratic mandate" and it hoped the presiding officer would "allow democracy to prevail".
A spokesman said: "The Brexit Party did not stand and were not elected in the 2016 elections.
"They have no democratic mandate and they should not be permitted to form a group nor given access to public resources and funding in the Senedd.
"To permit them to form a group would make a mockery of our democratic system in Wales."
Welsh Labour said the group had "no interest in Wales".
Agencies contributed to this report.
