BORIS Johnson has avoided answering a question about his plans to increase the number of nuclear warheads stored in Scotland by claiming the SNP MP had actually been asking about an independence referendum.

Although the SNP’s Peter Grant had asked about “the moral and democratic” justification behind the nuclear arsenal increase, the Prime Minister said independence “is all [the SNP] seem able to talk about”.

Grant had been following up on a question from his party’s leader at Westminster, Ian Blackford, which the Prime Minister had “refused point blank to answer”.

Speaking at today’s PMQs, Blackford had pointed to the 40% rise in nuclear warheads to be stored at the military bases at Faslane and Coulport.

READ MORE: Scottish Government hammers Boris Johnson over nuclear warhead plan

He said: “Every single one of these weapons will be based on the Clyde, so can the Prime Minister tell us when the people of Scotland gave him the moral or democratic authority to impose these weapons of mass destruction on our soil?”

Johnson replied: “The people of Scotland contribute enormously to the health, happiness, wellbeing and security of this entire country, not least through their contribution to our science, our defences, our international aid and many many other ways.

“I’m very proud that this government is investing record sums in defence, including maintaining our nuclear defence which is absolutely vital for our long term security and helping thereby to drive jobs not just in Scotland but across the whole of the UK.”

Slightly later at PMQs, Grant, who represents Glenrothes for the SNP, asked Johnson a similar question.

He said: “The Prime Minister refused point blank to answer the question from [Blackford], so I’ll ask him again.

READ MORE: Ruth Wishart: Tories are turning breaking international law into a wee hobby

“What is it that gives any British Prime Minister the moral and democratic right to impose the obscenity of an even bigger arsenal of weapons of mass murder on the people of Scotland against their express will?”

Johnson claimed Grant’s question had in fact been a “veiled” attempt to ask for a second independence referendum.

He said: “I think that was a veiled attempt again by the SNP to ask for another referendum which is their habitual refrain, that is all they seem able to talk about, democractic wrangling about democracy and their desire to be separated and to break up the country.”

Grant could be seen shaking his head as the Prime Minister went on: “I don’t think that’s the right way forward. I think we need strong defences. That’s what the people of this country voted for, and that’s what we’re going to deliver.”

Johnson’s plans to increase the number of nuclear weapons kept on the Clyde have caused outrage north of the Border, with Justice Secretary Humza Yousaf branding it “utterly unacceptable”.

The First Minister also took to Twitter to highlight what she sees as the difference between the UK and Scottish Governments.

She wrote: "Today, the UK government will announce a massive increase in its stockpile of nuclear weapons. By contrast, @scotgov will incorporate the UN Convention on the Rights of the Child into Scots law."