Addressing a press conference in New Delhi in India, Mr Johnson said the Government was contemplating sending Challenger 2 tanks to eastern Europe to replace Soviet-era T-72 tanks the Poles are shipping to Ukraine. According to the Pentagon, Ukraine’s military now has more tanks on the battlefield than Russia does.
Mr Johnson told reporters: “I think perhaps what I haven't said publicly before is we're also looking more at what we can do to backfill in countries such as Poland who may want to send heavier weaponry to help defend the Ukrainians.
“So we're looking at sending tanks to Poland to help them as they are sending some of their T-72s to Ukraine.”
It was reported last month that Ukraine had more tanks as of March than it did at the start of the war.
At the time of Russia’s invasion, the country boasted around 2,000 tanks.
The Challenger 2 tank has been the mainstay of the British Army since the 1990s and saw action in the Iraq War.
The 64-tonne vehicles are due to go out of service in 2025, but the Army still has a fleet of more than 200.
Meanwhile, German Chancellor Olaf Scholz said he feared that sending tanks directly to Ukraine could spark a third world war.
He told Spiegel: “We need to do everything to avoid a direct military confrontation between NATO and a heavily armed superpower such as Russia, a nuclear power.
“I will do everything to avoid an escalation that could lead to World War III – there can be no nuclear war.
“That's why it is all the more important that we consider each step very carefully and coordinate closely with one another.
“To avoid an escalation towards NATO is a top priority for me.
“That's why I don't focus on polls or let myself be irritated by shrill calls. The consequences of an error would be dramatic.”
The UK is already one of the biggest donors of weapons to Ukraine, with the Ministry of Defence supplying hundreds of anti-tank missiles, along with anti-aircraft and anti-ship missiles, ammunition and medical supplies.
More than 20 soldiers arrived last week in the UK for training on the 120 vehicles being supplied to Ukrainian president Volodimir Zelensky's resistance as Boris Johnson steps up military support to help in the war.