The papers on Sunday are led by an exchange of warnings between Vladimir Putin and the West.

The Observer and The Independent report the Russian president has told Western leaders that the sanctions imposed on his country were “akin to an act of war”.

Meanwhile, The Sunday Telegraph leads with Defence Secretary Ben Wallace warning Putin not to “test” the UK.

It comes as The Sunday Times and Sunday Mirror say “merciless Putin” broke a temporary ceasefire when Russian forces shelled evacuees fleeing the besieged city of Mariupol.

The Sunday Express carries comments from Foreign Secretary Liz Truss, who calls the Ukraine crisis the “struggle of our generation”.

The Mail on Sunday reports Prime Minister Boris Johnson has a “six point plan” to defeat Mr Putin.

Sunday People leads with British dockers refusing to unload Russian oil from a tanker on Saturday.

And the Daily Star Sunday says US and UK spies have claimed Mr Putin is “dying of cancer”.