The Challenger 2 tanks the UK is supplying to Ukraine are expected to arrive in the war-torn country at the end of March.

Prime Minister Rishi Sunak said “everything is going according to plan” over the supply of the tanks, with Ukrainians expected to start training on the Challengers shortly.

The UK was the first country to promise modern Nato tanks to Ukraine, with Germany and the US now also committed to supply Volodymyr Zelensky’s forces with dozens of vehicles.

Speaking at Chequers, where ministers were gathered for a Cabinet away day, Mr Sunak said: “Everyone should feel very proud of the leadership role that we here in the UK have played.”

He added: “We are now in dialogue with the Ukrainians about how best to provide those tanks and make sure their troops get the training they need on them as well.

“Those conversations are happening, everything is going according to plan.”

In the Commons, defence minister Alex Chalk said the UK will begin training Ukrainian soldiers in how to use and fix the contingent of tanks “next week, on Monday”.

On when Challenger 2 tanks would arrive in Ukraine, he added: “The intention is that it will be at the end of March, and between now and then a really significant programme of training, not just for the tank crews who are to operate this vehicle, but also for those who will be charged with maintaining it.”

He stressed that equipping Ukraine to push Russia out of its territory is “as important as equipping them to defend what they already have”.

Responding to Mr Chalk’s statement, Labour welcomed the move by the UK and Nato allies to send tanks to Ukraine but also urged ministers to replenish the UK’s supply of arms after its donations.

Shadow defence minister Rachel Hopkins said: “The UK remains united in its support of Ukraine. The first package of UK military assistance for 2023 with tanks, artillery, infantry vehicles, ammunition, and missiles has Labour’s fullest support.”

She then pressed the minister on what steps he is taking to “ramp up production of ammunition and equipment to restock our own armed forces and to support Ukraine”.

“It took 287 days into the start of the invasion for the Defence Secretary to get his act together and sign a new contract to replenish N-Laws (anti-tank weapons) for our armed forces and for Ukraine,” she said.

“So how many more contracts have been signed to replenish UK stockpiles of other weapons sent to Ukraine?”

Mr Chalk suggested that discussions on restocking the UK’s military supplies are too sensitive to be had on the floor of the Commons.

He said: “On the issue of restocking, she is right. She will understand that there are operational sensitivities which mean that I can’t go into the detail of exactly what is going to be restocked and when.

“But she will know – and the privy councillors including from the Opposition have been given a briefing on that – that is exactly what we should be doing to ensure that those who need to know these sensitive details are told what they properly can be.”

Meanwhile, Labour MP Kevan Jones also spoke about the “effects of these donations on our Army’s capability”.

“He talks about 227 Challenger 2 tanks. He knows that actual operational it’s far less than 100. So what is he going to do to actually ensure that those alarm bells that have been sounded by the Chief of the General Staff are met with new capabilities so we can meet our Nato commitment?” he asked.

Mr Chalk said it is “important” to make the point that “weapons that we supply have the effect of degrading the very adversary that was noted in the IR (Integrated Review)”.

He added: “So, not only is this a just war where we are there to stand up for the international rule of law – we are there to make a statement that might is not always right, that you can’t remake borders by force – but also it’s there to degrade the forces of our principal adversary as identified in the IR.”

He then pointed to comments made by Defence Secretary Ben Wallace that a further squadron of Challenger tanks will be brought to higher readiness, “ready to deploy in the defence of this nation”.