British Labour leader Keir Starmer will face a fresh battle with the party's left amid accusations that the resignation of Andy McDonald from the shadow cabinet was an act of "planned sabotage" by critics of the party leader.

The Labour conference will vote on a motion from the Unite union calling for a £15-an-hour (€17.5) minimum wage - the issue which led to Mr McDonald dramatically quitting Mr Starmer's team, claiming he had been ordered to argue against the hike in pay rates.

The resignation has overshadowed Labour's efforts to set out crime and health policies at the gathering in Brighton, England.

Shadow Scottish secretary Ian Murray said: "We're not quite sure why he resigned yesterday, he seems to have said one thing and written another.

"That looks as if it might be a planned sabotage of conference, rather than it being about any principle."

He told BBC's Good Morning Scotland: "We're all very angry and frustrated that the headlines are being dominated by one person when we should be talking about the big issues of the future."

Shadow home secretary Nick Thomas-Symonds defended Mr Starmer's "strong leadership" after the leader succeeded in getting a package of internal rule changes through conference despite opposition from the left.

But he insisted the leader's actions were not an attempt to "defeat" the Jeremy Corbyn-supporting wing of Labour.

Mr Thomas-Symonds said: "What we have seen this week is, firstly, the changes to the leadership rules which were passed, and there was doubt as to whether they were going to be passed, but they were.

"It showed strong leadership from Keir and a determination that we would face outward to the country."

He told BBC Radio 4's Today: "It isn't about defeating different bits of the party, the party has always been a broad church, but what we are doing is showing a very firm sense of direction under our new leadership.

"Keir has shown that very strong sense of direction this week, he has got the rule changes through and we will be getting those policies out to the country now as well."

Mr Thomas-Symonds said Labour would assess its policy on the minimum wage closer to the next general election.

He told Sky News: "We are very committed to a minimum wage of at least £10 an hour.

"But it is the responsible thing as we get closer to the election, to look at the rate of inflation, rate of wages, the wider economic situation for the precise figure that we will put before the country at the next general election."

He added: "I wish Andy well on the backbenches."

Mr McDonald said he quit as shadow employment rights secretary after being ordered to argue against a national minimum wage of £15 per hour and against statutory sick pay at the living wage ahead of today's vote.

"This is something I could not do," Mr McDonald wrote.

In his resignation letter, he told Mr Starmer: "After 18 months of your leadership, our movement is more divided than ever and the pledges that you made to the membership are not being honoured."

Mr Starmer responded: "My focus and that of the whole party is on winning the next general election so we can deliver for working people who need a Labour government."