The slip-up came during his first major contribution as a key MP after being ousted from the prime ministership. In a public debate on the war in Ukraine, Mr Johnson said it was important to “redouble our defense of Ukrainians” if Mr Putin redoubled his “aggressiveness”. Latest war in Ukraine: Russian foreign minister speaks at UN As he listed the reasons why Ukraine’s counteroffensive is proving successful, however, he inadvertently thanked Mr Putin, before quickly correcting himself to thank Mr Zelensky. He said: “Thanks to the heroism of the Ukrainian armed forces, thanks in part to the weapons we are proud to offer, I congratulate my right hon. friend (James Heappey) for describing the work of the UK armed forces. the weapons we send, the huge list… “Thanks also, of course, to the inspirational leadership of Vladimir Putin.” Mr Johnson immediately realized his mistake and added: “The inspired leadership of Volodymyr Zelenskyy, excuse me, Russian forces have been driven out in recent days from large areas of the north-east around Kharkiv. “And they are under increasing pressure in Kherson in the south, and I have no doubt that the Ukrainians will win.” It was the second time the MP for Uxbridge and South Ruislip has made a contribution to the Commons. In his first appearance since resigning as prime minister, Mr Johnson paid tribute to the late Queen Elizabeth at the special two-day event in Parliament. Read more: Boris Johnson calls himself ‘booster missile’ in final speech as PM James Smart calls on countries to reject Putin’s ‘fake’ Ukraine referendum During his speech on Ukraine, Mr Johnson also said the UK should be ready to provide “more military aid” and “more financial support” to Kyiv. He said: “If Putin is going to redouble his aggression, then we have to redouble our defense of Ukrainians and we have to be ready to offer more military aid and more financial support, and I warmly welcome the announcements from that. government this week.” Mr Johnson also warned against encouraging the Ukrainians to do a “land trade for peace” deal to allow Russian gas to flow to Europe. Support for Ukraine was a key policy during Mr Johnson’s premiership. He was a close ally of Mr Zelensky and visited the war-torn country three times within seven months of its invasion. His last visit was at the end of August, when he said high energy bills were something UK households had to endure as part of a bid to resist Putin. Shortly before leaving office, Mr Zelenskyy wrote an op-ed for the Mail on Sunday in which he heaped praise on the former prime minister, describing him as a “true friend” and “ally”.