Liz Truss has joined growing calls for fighter jets to be sent to Ukraine, in her first speech in Parliament since resigning as prime minister.
Ms Truss said the UK needed to “do all we can, as fast as we can” to help Ukraine win the war against Russia.
The call was echoed by former PM Boris Johnson during a debate on Ukraine, putting pressure on PM Rishi Sunak.
Mr Sunak’s government has agreed to train Ukrainian pilots but says supplying jets is a long-term option.
Earlier this month, Ukrainian President Volodymyr Zelensky appealed to European leaders to supply his country with modern fighter jets during visits to the UK, France and Belgium.
The UK is to start training Ukrainian forces to fly Nato – standard jets and Mr Sunak has said “nothing is off the table”.
At the Munich Security Conference last week, the prime minister urged world leaders to give Ukraine the most advanced weapons to defend itself in the long term.
But Defence Secretary Ben Wallace has said there will be no immediate transfer of UK fighter jets to Ukraine.
He told the BBC it could take months to train pilots and the UK was instead focused on using alternative provision of air cover to the country.
Some Nato member countries are also worried that giving jets to Ukraine would be viewed as escalating the war, risking direct confrontation between the Western military alliance and Russia.