The ex-PM, making her first contribution from the back benches since her brief spell in No.10, said handing over British planes was part of making sure “Ukraine wins this war as soon as possible”.
Earlier this month, another former prime minister, Boris Johnson, said more than 100 Typhoon jets were held by the UK and “the best single use” for them would be in Ukraine.
Truss told MPs: “We need to do all we can to make sure Ukraine wins this war as soon as possible. Every extra day, a life lost, women violated, towns destroyed, we need to do all we can, as fast as we can.
“My view is that does include fighter jets and we have had a discussion today about which are the best possible options… having spoken to the Ukrainians about this, months and months ago, I know what they want is an option.”
Her call comes after Ukraine’s president Volodymyr Zelenskyy used an address to parliament to plead for combat aircraft, saying his country needed “wings for freedom”.
Last month, Ukraine got a huge boost from it Western allies after Germany and the US announced they would send coveted tanks to Ukraine despite weeks of hesitation.
It represented a big shift as the West is now providing arms that have a mainly offensive rather than defensive purpose.
Kyiv almost immediately began lobbying for fighter jets too – not least because its current fleet of warplanes are older than modern Ukraine itself.
The UK has so far refused to supply planes, arguing it would take years to train pilots to use the sophisticated F-35s and Typhoons in RAF service.
Sunak, however, has said “nothing is off the table” as talks continue.
On Monday, Johnson doubled down on his position, telling the commons: “Let’s cut to the chase and give them the planes too.”
He said: “If the house was in any doubt about the urgency of increasing our supply of equipment to the Ukrainians it is becoming ever clearer that China is preparing to arm the Russians.”
He added: “With the right kit, including more long-range artillery they can punch through the land bridge, cut off Crimea and deal a knock-out blow to Putin’s plans, and they should not stop there.”
“It is time for us all to end our obfuscation about what we think of as a Ukrainian victory and what we think of as Ukraine. The Ukrainians need to be helped to restore not just the borders of February 24 last year, but the 1991 borders on which they voted for independence.”