SINN Fein’s leader, Mary Lou McDonald, has suggested Westminster has “no interest in Scotland” and that the way Scottish MPs are treated there affirms her belief in her party’s abstentionism.

Sinn Fein's seven elected MPs do not take their seats in the House of Commons, despite repeated calls to do so during key Brexit votes.

On whether Sinn Fein would ever take their seats, Ms McDonald told the BBC’s Andrew Marr on Sunday programme that the seven votes would be ineffective and her party was resolute in their stance.

"I have no business in Westminster, we have no business in your parliament," declared the party’s leader.

"Westminster, correctly, advances and protects what it regards to be British interests. We have no business interfering in that. I am Irish; we have two parliaments and we advance Irish interests.”

She went on: "I look at the experience of our Scottish colleagues and I see them at Westminster, there's 30-odd, and they would readily attest that Westminster has no interest in Scotland either. Westminster has never served Irish interests, it's not constituted to do that; Irish interests are defended in Dublin and Belfast."

Ms McDonald added that the Good Friday Agreement would have to be revisited in the event of a hard Brexit on March 29 and an Irish unity referendum should be held.

"Put simply, if the border in Ireland cannot be mitigated, cannot be managed in the short term, well then you put the question democratically in the hands of the people and allow them to remove the border. Bear in mind the people of Northern Ireland did not consent to Brexit."

"The backstop is the bottom line. On the issue of the border poll, there's no point us burying our heads in the sand and wish away a hard Brexit. We prepare for the worst scenario and protect our national interest."

Ms McDonald told Marr that anyone gambling with peace on the island of Ireland was acting recklessly.

"One of the biggest symbols of success of the peace process is that people can travel unimpeded over the border.

"Any controls or checks or security checks, any question of British soldiers at the border - the Taoiseach has been clear there will be no Irish soldiers on the border- no one will accept the hardening of the border on our island.

"The peace process is very solid, very robust, we are only going forward and we are not going back, it would be grossly reckless and irresponsible of the Tories to play a game of chicken with that progress.

"Peace on this island is a precious thing, shame on anybody who would play games with that," added the Sinn Fein leader, who represents Dublin Central in the Irish Parliament.

But Labour’s Barry Gardiner hit back, saying he was very upset by Ms McDonald’s suggestion that Westminster was only interested in Britain.

“That is absolutely not the case,” declared the Scot. “Politicians in Westminster are working hard to make sure that all parts of the United Kingdom, including Northern Ireland, are considered and respected and upheld.

“The upholding of the Belfast Agreement, the Good Friday Agreement, is one of the central things we are looking to do,” insisted the Shadow International Trade Secretary.