Theresa May accused Nicola Sturgeon of "obsessive and divisive" nationalism as she defended her bold decision to block a second Scottish referendum before the UK splits from the EU at the Conservative Party Spring conference in Wales on Friday (17 March)

"We are now the party of the new centre-ground of British politics. Rejecting the extremes of Labour's socialist left, Ukip's libertarian right, and the divisive and obsessive nationalisms of Plaid Cymru and the SNP," the prime minister told the Tory delegates in Cardiff.

May went onto attack the SNP's pro-EU position as "muddle on muddle", pointing out that Sturgeon called for the second plebiscite between autumn 2018 and spring 2019 because the UK voted 52% to 48% for a Brexit, whilst 62% of Scottish voters backed staying in the EU.

"The SNP argue that we should break up the UK because we are leaving the EU, but three years ago they campaigned for a result that would have taken Scotland out of the EU altogether," she said.

"They are happy to see power rest in Brussels. But if those powers come back to London they want them given to Edinburgh so that they can try to give them back to Brussels.

"And now they apparently say that an independent Scotland would no longer seek to become a member of the EU after a vote for separation. It is muddle on muddle."

May added: "Our party believes heart and soul in our United Kingdom of Great Britain and Northern Ireland.

"The precious bond between four nations: England, Scotland, Wales and Northern Ireland. But that union is more than just a constitutional artefact. It is a union between all of our citizens, whoever we are and wherever we're from."

The impassioned speech, which received a standing ovation from the hundreds of Tory activists in attendance, comes just after Sturgeon accused May of "undemocratic" behaviour. "Any bid by the UK government to block the people of Scotland from making a choice will be untenable, undemocratic and totally unsustainable – and clearly shows that the UK government recognises it is out of step with the Scottish people," the First Minister of Scotland added.

Holyrood will vote on the issue next week, with the SNP holding their Spring conference in Glasgow on Friday. The 2014 Scottish independence referendum, granted by David Cameron, saw Scots rejected breaking away from the rest of the UK by 55.3% to 44.7%.