Sir Keir Starmer has called for an end to the fighting in Gaza “now” as he edged towards backing demands for an immediate ceasefire.

The Labour leader, addressing the Scottish Labour conference in Glasgow, added that an offensive that Israel is said to be planning in Rafah “cannot happen” and that the area “cannot become a new theatre of war”.

While he added that a ceasefire could not be “one-sided”, he repeatedly stressed on Sunday that he wanted to see an end to hostilities immediately.

He declared: “The fighting must stop now”.

Previously, Sir Keir has refused to back demands for an immediate ceasefire. He has instead stated support for a “sustainable” halt to fighting which would not mean Israel would be expected to unilaterally down arms.

The apparent shift in Labour’s position comes ahead of a Commons vote this week that threatened to reopen divisions over the issue.

Anas Sarwar, the Scottish Labour leader, has openly demanded an immediate ceasefire, in a call which was backed by Scottish Labour delegates.

While Sir Keir told the conference that he wanted to see the return of hostages taken by Hamas on October 7, he added that he also wanted “an end to the killing of innocent Palestinians” and “an end to the fighting”.

He added: “Not just now, not just a pause. But permanently. A ceasefire that lasts. Conference, that is what must happen now. The fighting must stop now.

“Any ceasefire cannot be one-sided. It must stop all acts of violence, on both sides, and it must lead to a genuine peace process.

“Because the offensive threatened in Rafah - a place where 1.5 million people are now cramped together in unimaginable conditions with nowhere else for them to go - this cannot become a new theatre of war.

“That offensive cannot happen.”

On Sunday, Mr Sarwar claimed that Labour was in talks with the SNP over their ceasefire motion.

A similar vote in November saw eight shadow ministers break ranks to back an immediate ceasefire, with some 56 Labour members defying a three-line whip and backing an SNP amendment to the King’s Speech.

David Lammy, the shadow foreign secretary, has declined to say how Labour MPs might vote.

“I haven’t seen the motion, it’s not yet put down, we will scrutinise that motion as is our way in Parliament and we will take it from there,” he told the BBC.

“But let us be clear, yes, we will have a vote in Parliament this week but it’s not that vote that will bring about a ceasefire, it’s the diplomatic action.”

He also sought to play down the idea that the party was divided on the issue.

“I fully understand that Scottish colleagues want the fighting to stop now, we’ve been saying that for weeks, so we agree with them.

“You can have a ceasefire that lasts for a few days. We want the ceasefire to last and to be permanent and to move towards the diplomatic solution. It will only be a political solution that brings an end to this.”

In an open letter to Labour MPs ahead of Wednesday’s vote, Stephen Flynn, the SNP’s Westminster leader, had told them that “the time for equivocation is over”.

However, he claimed on Sunday that claims that Labour were in talks with the party over the ceasefire motion were “not true”.

Mr Flynn added: “Nevertheless, I am more than willing to meet with Sir Keir Starmer to discuss this hugely important issue prior to Wednesday’s vote.”