Scottish National Party leader Alex Salmond says British politicians should apologise to Scotland, for 'disrespecting' the country's devolved parliament over its handling of a nuclear reactor leak, as he ramps up his campaign for independence.

In a statement, Salmond said that Prime Minister David Cameron should say sorry to Scotland after Westminster criticised its Scottish counterparts for the handling of a leak at a nuclear reactor based at the Dounreay site in Scotland.

"You must now offer an immediate explanation of why your government allowed this to happen, an apology for the disregard of established processes and a commitment that it will never happen again," said Salmond.

However, British Defence Secretary Philip Hammond said in a statement last week that the leak had not posed a safety risk and that nuclear regulators and Scottish environmental authorities and had been notified at the time.

Salmond refutes that this information had been passed onto the Scottish government immediately.

Scottish people will vote in an independence referendum on 18 September this year and will be asked the straight "yes/no" question: "Should Scotland be an independent country?"

The SNP has repeatedly promised voters that if it breaks the 307-year union with England, it will retain the pound, stay a member of the European Union, and still share a financial industry regulators and laws.

It also promised a nuclear-weapons-free Scotland if voters backed independence.

However, Salmond's scathing comments over the British government is the latest in a line of claims that it is bullying Scotland.

UK and European Union politicians have explicitly said that if Scotland breaks away from Britain, it will lose the currency, lose it EU membership, and be forced to create and uphold its own set of laws and watchdogs.