A British man accused of offering to sell information to Russia about Sir Grant Shapps claimed he was trying to “expose Russian agents” to help the Ukrainian war effort, a court was told.

Howard Phillips, 65, allegedly tried to help two intelligence officers who he believed were working for Moscow by passing on personal details about the former defence secretary.

He was unemployed and had applied for a job at UK Border Force, hoping the security clearance would give him access to more information.

It is alleged he believed he was in contact with two Russian Intelligence Service agents called Dima and Sasha, but they were actually undercover British police officers.

Giving evidence at Winchester Crown Court on Monday, Mr Phillips said he wrote a letter to the Russian embassy in early 2024 “portraying that I had information and if they were interested, they should contact me”.

He said he did not in fact have any information but wrote it “because of events that were happening in the world”.

“I was intending to track and expose Russian agents,” Mr Phillips said.

Asked by his lawyer Jeremy Dein KC what events he was referring to, he said: “In particular, the war between Israel and Gaza and the Ukrainian-Russian war.

“I was very frustrated with the delay in the US Senate agreeing to finance and provide weapons and material to Ukrainians.

“Watching every day the lines moving further into Ukraine by the Russian army.

“I felt the West wasn’t doing enough to stem the flow of Russian advance.

“I was intending to expose and track a Russian agent who may be operating within the UK. It was a small part to play … it was a small part that possibly I could do,” he added.

The court heard Mr Phillips’s finances were “decreasing rapidly” at the time but he denied asking for money when he wrote to the Russian embassy, saying he did not believe he would get any money that way.

He said he also wrote to the Iranian and Chinese embassies, with the same plan to assist Israel.

On April 4 2024 Phillips left the “agents” a USB stick on the exposed seat shaft of a bicycle parked on Polygon Road, London, near St Pancras and Euston stations.