Tuesday is the final day of a ballot for Russian-held regions of Ukraine which the government in Kyiv and its Western allies dismiss as a sham.

Nearly four million people from the eastern regions of Donetsk and Luhansk, and the southern regions of Kherson and Zaporizhzhia, are being asked to attend polling stations and vote in so-called referendums on joining Russia.

This follows four days of early voting during which allegations of intimidation multiplied as election officials went house to house accompanied by armed guards.

The votes, called with just a few days’ notice, serve a deadly serious purpose as they will be used by the Kremlin to legitimise its invasion aims.

If Russia absorbs these regions, making up about 15% of Ukraine’s territory, it could take the war to a new and more dangerous level, with Moscow portraying any attempt by Ukraine to regain them as an attack on its sovereign territory.

There is now speculation that Russian President Vladimir Putin may announce the four regions’ annexation in a speech to a joint session of Russia’s parliament on Friday.

In March 2014 he announced that Ukraine’s Crimea Peninsula had been annexed just a few days after a likewise unrecognized referendum was held.