LONDON — Pity poor Scotland. Within days it has been warned that if it has the temerity to vote for independence in September it can forget about a currency union with the pound and forget about becoming a member of the European Union, two ideas Scottish nationalist leaders have presented as entirely feasible.

The first warning came from George Osborne, the British chancellor of the Exchequer, who declared that, “If Scotland walks away from the U.K. it walks away from the U.K. pound.” He added that “there’s no legal reason why the rest of the U.K. would need to share its currency with Scotland.”

The second was delivered by José Manuel Barroso, the European Commission president, who told the BBC it would be “extremely difficult, if not impossible,” for Scotland to join the European Union because it would require the unanimous approval of other member states. That was a remote possibility given the dim view taken by some countries, notably Catalonia-fearing Spain, on secession. Spain, Barroso noted, had not recognized Kosovo, which broke away from Serbia.

“Bluff, bluster and bullying” was the verdict of Alex Salmond, the leader of the Scottish National Party and the campaign for independence, to Osborne’s apparent threat. John Swinney, Scotland’s finance minister, called Barroso’s remarks “pretty preposterous.” Scots, both men suggested, would not be cowed.