On a bank holiday visit to Y Barri on Monday (3 May), the UK's Prime Minister Boris Johnson accused Welsh Labour of "separatism".
Johnson visited the Conservative Party office in the town centre, as he joined his party on the campaign trail ahead of the election on Thursday (6 May).
In the previous Senedd election, the constituency of Bro Morgannwg was won by Labour, but in the 2019 UK General Election, the Conservatives took the seat.
Johnson told the BBC he wants to see "politicians working together to beat the pandemic."
First Minister Mark Drakeford is opposed to independence, but is in favour of devolving more powers, such as policing and justice, to the Senedd.
However, Plaid Cymru, with whom Labour might have to strike a post-election deal, has pushed independence to the forefront of its election campaign.
Talking to the BBC, Johnson said: "I don't think the people of this country are obsessing right now about further constitutional change."
He also said that he is a "believer in devolution". but in November 2020, he reportedly called devolution Tony Blair's "biggest mistake" and "a disaster north of the border".
Johnson accused Labour and Plaid Cymru of being "obsessed" with "constitutional issues", and of "trying to go for more separatism".
"I think we should have a situation which people can be proudly emphatically Welsh, but also see the merits and the beauty of doing things together."