BORIS Johnson has exposed his hypocrisy over rejecting the plan for a Scotland-based immigration system, saying it is an "absolutely fanciful" idea.

The 94-page Scottish Government report called Migration –Helping Scotland Prosper was sent to Westminster this week but was rejected by the Home Office within minutes.

The idea could have satisfied England's hardened immigration policies while allowing Scots to prosper.

READ MORE: Home Office swiftly dismisses Nicola Sturgeon’s migration proposals

SNP Westminster leader Ian Blackford brought up the issue at Prime Minister's Questions. He said: "During the EU referendum the Chancellor for the Duchy of Lancaster said that when it comes to immigration it would be for the people of Scotland to decide.

"On Monday the Scottish Government published its plans for a Scottish visa, doing just what the right honourable member promised Scotland should be able to do. Before the ink was even dry, these proposals were rejected without consideration."

The PM responded: "I think the idea of having a Scottish-only visa with a border at Berwick ... I think this is absolutely fanciful."

He went on to say that he doubts the document "explains who is going to pay for it".

Blackford hit back, saying: "Nobody suggested such a thing and that just confirms the Prime Minister doesn't have a clue."

He pointed out that experts like the Federation of Small Businesses, the Scottish Trades Union Congress and the Scottish Council for Development and Industry support the Scottish Government's proposals. 

"Even the MAC [Migration Advisory Committee] report commissioned by his own government has highlighted additional migration routes as a means of increasing population."

The MAC – which provides independent, evidence-based advice to the Government – made a string of recommendations after reviewing plans for an Australian-style points-based immigration system set to be introduced after Brexit.

READ MORE: Ben Macpherson: Points-based immigration system 'ignores Scotland'

Blackford continued: "We were told we would have the most powerful devolved parliament in the world, we were told we'd be an equal partner in the family of nations. Will the Prime Minister now read the Scottish Government proposal ... and deliver a tailored migration policy for Scotland."

Johnson said the SNP should "get on with the day job" and criticised Thursday's debate over whether the Council of Europe Flag will stay at Holyrood after Brexit.

READ MORE: Scottish Government moves to stop EU flag being taken down at Holyrood

Watch the full exchange below