A senior UK minister sought Monday to defuse tensions with the constituent nations of the United Kingdom and insisted that powers returned from Brussels would be fairly shared when Britain leaves the EU next year. David Lidington warned that some nationalists wanted to use the opportunity offered by Brexit to loosen or even sever the centuries-old ties that have bound England, Scotland, Wales and Northern Ireland into a single country. “Such an outcome would leave every one of our four nations both weaker and poorer,” he said in a speech in Wales. “We are all more prosperous and more secure when we all work together for our common good as one United Kingdom,” said Mr Lidington, the effective deputy of premier Theresa May. Politicians in Wales and Scotland have been sharply critical of the London-based government’s approach to Brexit and the question of who would administer new powers over issues such as fishing rights and the environment after March 2019. Scotland, Northern Ireland and Wales were all given extra powers as part of a devolution drive started by the former premier Tony Blair in the 1990s. But while Scotland rejected full independence in 2014, it bucked the UK trend and voted to remain within the EU in the 2016 referendum. Nicola Sturgeon – Scotland’s first minister and head of the pro-independence Scottish National Party (SNP) – has abandoned plans for another independence vote until after Brexit but has insisted she will not agree to a “power grab” from Westminster. Mr Lidington said on Monday that the Westminster, London-based government made a "considerable offer" to commit to sending the vast majority of powers being brought back from the EU to the Edinburgh, Cardiff and Belfast. He said it was always the government’s intention for “wide-ranging devolution not just away from Brussels, but from Westminster, too.” But he said that some powers are clearly related to the UK as a whole and will continue to apply across all nations. Mr Lidington’s appeal for unity was rejected by Scotland's Brexit minister, Michael Russell, a member of the SNP. “The UK government's approach to date makes a mockery of claims of a partnership of equals,” he said.