A DROP of almost 20 per cent in Labour members in Scotland has been put down to the “natural cycle” of politics by one of the party’s MPs.

The interpretation of the fall in membership figures by Glasgow North East MP Paul Sweeney came as the SNP claimed Scottish Labour was facing "terminal decline".

A poll over the weekend put Labour across the UK seven points behind the Tories at 41 to 34 per cent and there was talk of a group of Labour MPs contemplating a breakaway to form the core of a centrist grouping at Westminster.

Papers leaked to The Herald on Sunday showed Scottish Labour’s membership fell from 25,836 in January 2018 to 21,162 last month – a drop of 4,674.

The number of Labour members in the party's former Glasgow heartland fell by 1,545 in the last 12 months, with membership over the nine constituency branches in the city dropping from 5,814 to 4,269.

In the Eastwood Constituency Labour Party branch alone, membership was down from 621 in January 2018 to 385 last month – a reduction of 38 per cent.

Kirsty Blackman, the SNP's deputy leader at Westminster, claimed the numbers showed Labour was "on the path to terminal decline and total irrelevance in Scotland".

The Aberdeen North MP added: "No-one will be surprised that their toxic support for Tory plans to drag Scotland out of the EU against our will has led to a mass exodus of party members right across the country."

But Labour sources were keen to point out that the number of members the party had in Scotland almost doubled since the time of the independence referendum in 2014.

Mr Sweeney explained the fall in membership was part of a "natural cycle" because Scottish Labour had a leadership election in 2017, which saw Richard Leonard elected as party leader in November of that year, ahead of his rival MSP Anas Sarwar.

Speaking on BBC One's Sunday Politics Scotland show, the Shadow Scotland Office Minister said: "As many people who are familiar with party political dynamics will know, many people join parties in order to participate in leadership elections."

It was reported earlier this year that Labour’s UK membership had suffered a fall of more than 100,000 from its height of around 550,000, put down in large part to the stance on Brexit taken by Jeremy Corbyn and his senior colleagues in the Shadow Cabinet.

It was suggested at the weekend that at least six Labour MPs were considering resigning the party whip soon and forming a breakaway centrist movement.

One Labour rebel dismissed such talk as "kite-flying", but the suggestion was seized upon by Sir Vince Cable, the Liberal Democrat leader, who said there was a "real chance of a significant group" of Labour MPs breaking away from their party and that, if that happened, then the Lib Dems would “work with them in some form".

Elsewhere, Baroness Chakrabarti, the Shadow Attorney General, played down the idea that Labour MPs in Leave areas would accept "bribes" from Theresa May to support her Brexit deal.

After reports last week suggested the Prime Minister was prepared to offer incentives to opposition MPs in the poorest areas to break the whip, Lady Chakrabarti said: "I don't believe in the end that any Labour MP would really be fooled by what some people have called a bribe.

"That is not because Labour constituencies, like vast parts of the country, are desperate for more investment, it's because you can't just pick constituencies off in that very narrow sort of way."

The Labour peer added: "I do not believe Labour voters and the most left behind constituencies would thank their MPs for these short-term isolated bribes. I just don't see that commanding public confidence and support.

"When you think about how disenchanted people have been with politics and politicians in recent years, the idea that would be reversed by this sort of pork barrel politics, I just don't see it."