Momentum on Ukraine has “dropped back” since Labour took office, according to the ex-Tory defence minister and former army officer Sir Ben Wallace.

Responding to recent comments by Kyiv officials that Ukraine’s relationship with the UK has “got worse” since Keir Starmer was elected prime minister, Wallace said that was because “the leadership that Britain showed right from the start has started to drop back into the pack”.

In an interview on the Today programme on BBC Radio 4, Wallace said that in his experience, officials in the Foreign Office would often tell the defence minister “we don’t want to get ahead of the pack – in other words, we don’t want to have any leadership – we just want to sort of dwell in the middle”.

Starmer has yet to visit Ukraine four months after taking office, and a senior figure in Volodymyr Zelenskyy’s government voiced frustration on Friday over Britain’s failure to supply Ukraine with additional long-range missiles.

The Kyiv official told the Guardian: “It isn’t happening, Starmer isn’t giving us long-range weapons. The situation is not the same as when Rishi Sunak was prime minister. The relationship has got worse.”

Fears are growing in Ukraine that Donald Trump’s victory could reduce US military aid, and Kyiv is desperate for Starmer to commit to replenishing stocks of the sought-after Storm Shadow system.

Wallace said one reason the Conservative government had supplied Ukraine with weapons systems in the past was to show leadership. “We took a position to lead and the leadership did bring lots and lots of Europeans with us … I definitely have a sense that that momentum has dropped back.”

To drive change in government took perseverance and determination, he suggested. “You have to really do it every single day. You can’t just do a statement and then float around,” he said.

He said companies seeking to export equipment that would help Ukraine had been waiting six months for their export licences to be processed. “That doesn’t sound like a government that wants to help Ukraine, if its bureaucracy in the Foreign Office is holding out some pretty basic technologies that Ukrainians need to make their own weapons systems to defend their nation.”

Earlier this week, Starmer said he strongly believed allies must “step up” support for Ukraine as he met Zelenskyy one on one on the fringes of a political summit in Budapest. He told the Ukrainian president the UK had an “unwavering” commitment to help the country defend itself against Russia’s invasion.

He said: “It’s very important that we see this through. It’s very important that we stand with you.”

Zelenskyy replied: “We’re very thankful. We’re very proud that we have such bilateral relations between our nations.”

Britain and France said in 2023 they would supply Ukraine with Storm Shadow missiles, highly accurate long-range cruise missiles developed by an Anglo-French collaboration.

But although the last Storm Shadow strike claimed by the Ukrainian military was on 5 October, targeting Russian command posts, the number of such strikes by Ukraine has dwindled throughout 2024. “You would know if the UK had provided us with new Storm Shadow missiles because we would be using them to hit Russian targets. We are not,” the Kyiv official said on Friday.

Storm Shadow missiles are expensive, at an estimated £800,000 a unit, but are considered effective against static targets and have been used to strike at Russian naval assets in Crimea.