An ex-defence chief says the West must "tread extremely carefully" around Vladimir Putin after the invasion of Ukraine.

Sir Gerald Howarth, who served as a defence minister between 2010-12 and now lives in Chelsworth, likened the Russian leader to a "wounded animal" and said western governments must avoid backing him into a corner.

Sir Gerald said: "The Ukrainian people have been utterly heroic. They have prevented Putin's invasion from going according to plan.

"But that, of course, has led to two alternative outcomes. One is if Putin wins Ukraine, he is in complete violation of a treaty signed by his predecessor. He's subjugated a sovereign state again. And where will he go next?

"But if he fails, he will be very much like a wounded animal licking its wounds. He is likely to respond completely – in our terms – irrationally.

"We've already seen his sabre-rattling about resorting to nuclear weapons."

Sir Gerald, who was also chairman of the all-party parliamentary group on Ukraine, said Western leaders had been wrong about Putin's intentions before and should not disregard this as an empty threat.

On Sunday, Vladimir Putin put Russia’s strategic nuclear weapons forces on high alert.

Kremlin spokesman Dmitry Peskov blamed the escalation on remarks given by foreign secretary Liz Truss, although it is not clear which remarks he was alluding to.

"There's no question about it, this is a warning shot," Sir Gerald said. "We didn't think he would invade Georgia. We didn't think he'd annex Crimea. We didn't think he would invade Ukraine. He's done all of these things.

"If I were still in a leadership role in the country, I would be erring on the cautious side and positioning the country to prevent there being any miscalculation while making sure that we were prepared.

"I don't want to sound armageddon-ish, but I think in a world of realpolitik it would be foolish to make an assumption he wouldn't do as he has done on every other occasion when he we thought he wouldn't do it.

"We have to try to make sure somehow that we don't push the guy into a corner.

"It's not easy. This is calling for very considerable political, diplomatic and military skills."