LABOUR has suffered a drubbing in Scotland and setbacks south of the border in elections seen as the first nationwide verdict on Jeremy Corbyn's leadership of the party.

Scottish Conservative leader Ruth Davidson made clear she expected to head the main opposition party at Holyrood as Labour looked set to slump into third place in Scottish Parliament polls, losing more than nine points in its share of the vote.

READ MORE: Kezia Dugdale backed to stay on as Labour leader despite vote collapse

In highly symbolic results, Labour lost the totemic Rhondda seat in the Welsh Assembly to Plaid Cymru leader Leanne Wood and saw the Scottish National Party pull off a clean sweep of seats in its one-time stronghold of Glasgow.

While Labour held on to two safe seats in Westminster by-elections and losses in English councils were less deep than some predicted, frustrations with Mr Corbyn's leadership bubbled to the surface.

Backbench MP Neil Coyle warned the party was "moving away from government" under the veteran left-winger, while the leader of the Labour group on Portsmouth Council, John Ferret, denounced him on BBC Radio as "incompetent" and "incapable of giving the leadership we need". Bassetlaw MP John Mann said third place in Scotland would be "cataclysmic" for Labour.

Meanwhile, shadow cabinet minister Andy Burnham revealed he was considering running for mayor of Greater Manchester, in an apparent sign that pessimism about Labour's prospects of regaining power at Westminster reaches into the party's highest echelons.

With counting yet to begin in elections to the Northern Ireland Assembly, London mayoralty and Police and Crime Commissioners, highlights from the overnight results included:

:: Labour losing 13 Scottish Parliament seats, including 11 to the SNP and two to Conservatives.

:: Ms Davidson securing a seat at Holyrood by winning Edinburgh Central from the SNP, while Scottish Labour leader Kezia Dugdale was left relying on the top-up system for a seat as she failed to take Edinburgh Eastern.

:: A bounceback by Liberal Democrats north of the border saw leader Willie Rennie return to Holyrood in North East Fife, while the party also took Edinburgh Western from the SNP and held on to the Orkney and Shetland islands.

:: Labour lost control of Dudley council in the West Midlands, but held on to major cities including Birmingham, Newcastle-upon-Tyne and Sunderland, as well as key southern outposts like Exeter, Southampton, Crawley and Slough . With results in from 76 out of 124 councils, Labour was down by 10 seats, Ukip up 21, Conservatives up 15 and Lib Dems up six.

:: Conservatives lost overall control of Worcester but secured an absolute majority in Peterborough.

:: Ukip gained seats in Thurrock, Tamworth and Bolton and looked set to secure its first representation on the Welsh Assembly.

Conservative Cabinet minister Chris Grayling told BBC News: "The story of tonight is the erosion of the foundations of the Labour Party. It has been almost decimated in Scotland, it is now losing core areas of Wales. Labour losing the Rhondda is a huge blow to that party. We are seeing Labour lose its foundations because it has become utterly out of touch with the public as a whole."

READ MORE: Kezia Dugdale backed to stay on as Labour leader despite vote collapse

Labour had retreated on the eve of polling from Mr Corbyn's earlier prediction that it would lose no seats. As results came in, senior figures including shadow chancellor John McDonnell set the modest aim of reducing the 6.3% advantage recorded by the Conservatives in the 2015 general election.

In her victory speech in Edinburgh, Ms Davidson said she was ready to lead "the main opposition party" in the Scottish Parliament.

SNP leader Nicola Sturgeon said Labour had suffered "quite staggering" losses in Scotland, which Mr Corbyn identified as a top priority shortly after winning the leadership in September.

On the brink of securing her first personal mandate as First Minister, Ms Sturgeon said her party had "made history" by topping the Scottish Parliament polls for the third time in succession, describing the result as "a vote of confidence in the record in government of the SNP and a vote of trust in the SNP to lead our country forward".

There were signs that the recent row over anti-Semitism had damaged Labour, with a large swing to Conservatives losing Labour the Sedgley ward in Bury, and the Eastwood constituency in Scotland, both of which have significant Jewish communities.

Deputy leader Tom Watson urged Labour activists and MPs to "respect the mandate" given to Mr Corbyn by members and supporters last year, and suggested that it was too early in his tenure to expect him to be chalking up significant electoral advances.

"I think most people would recognise you can't consolidate your position in only eight months," Mr Watson told Sky.

But Bermondsey & Old Southwark MP Mr Coyle told BBC2's Newsnight: "We are moving further away from government, I think, because we seem to be fixated on some issues that are peripheral and we seem to have a team which isn't projecting either unity within the party or a vision and policies that the voters want."

Labour's victor in the parliamentary by-election in Sheffield Brightside was Gill Furniss, widow of Harry Harpham, whose death from cancer after just eight months as an MP triggered the poll in David Blunkett's former seat.

Her success, on a 4% swing from Ukip, was followed by a second by-election victory in the safe Labour seat of Ogmore, in south Wales, where Chris Elmore took more than 50% of the vote as Ukip and Plaid Cymru forced Conservatives into fourth place.

But elsewhere, it seemed that Labour's next hope for a significant advance may not come until Friday evening, when Sadiq Khan is expected to take back City Hall in London after eight years of Tory rule.

Ukip leader Nigel Farage said his party was "biting hard" into the traditional Labour vote, which he claimed was being turned off by extremism which went "right to the very top" of Mr Corbyn's party.

Labour's Carwyn Jones looked set to remain First Minister in Wales, but may have to seek a coalition partner as the party struggled to maintain its overall majority in the Welsh Assembly.

Ms Wood said her victory on a 24% swing in Rhondda showed that "a new dawn is about to break in Wales", while former Cabinet minister Lord (Peter) Hain described the result as "a terrible shock for us in Welsh Labour".

There was better news for Labour in Liverpool, where Joe Anderson was re-elected as mayor with more than 50% of the vote.

Communities Secretary Greg Clark told ITV1's Good Morning Britain: "Normally oppositions expect to make gains mid-term. When Michael Foot was elected Labour leader, in his first year he made nearly 1,000 gains. So for Labour to have a high-water mark with what Ed Miliband achieved and they are now receding from that, I think is a big upset.

"Senior figures like Michael Dugher, their former campaign chief, said they should be looking at 400 gains. That's the kind of progress you need to make in opposition for you to get into government.

"I think what it shows is that the party under Jeremy Corbyn is losing touch with the ordinary working people of the country. Not only are they not making any progress, they are going backwards."

READ MORE: Kezia Dugdale backed to stay on as Labour leader despite vote collapse