Remembrance Day: Tower of London poppy buyers warned they could crack in cold

The ceramic flowers are being removed and delivered over the coming weeks

A general view at the 'Blood Swept Lands and Seas of Red' evolving art installation at the Tower of London

Owners of the Tower of London poppies are being warned that the ceramic flowers could crack in the cold if they are left outside over winter.

The fear is believed to be one of the reasons that calls to extend the astoundingly popular Blood Swept Lands and Seas of Red installation have not been fully answered, the Sunday Times reported.

Historic Royal Palaces, which runs the Tower, told the paper the main reason why the poppies had to be removed - despite appeals for them to stay by politicians including the Prime Minister and Boris Johnson - was because of a pledge to deliver them to buyers by January.

If they had stayed, sellers would have broken the promise and despite the poppies being insured, a spokesperson said they might be damaged by cold weather.

Four million people were expected to have seen the display of 888,246 handmade poppies by Armistice Day, after the size of crowds caused the closure of nearby train stations and led to the installation being illuminated until midnight in efforts to spread visitor numbers.

Huge crowds have flocked to see the Tower of London poppies (Getty)

David Cameron announced that parts of the First World War installation would be extended until the end of November after weeks of public campaigning.

The Weeping Willow and Wave segments of the display, pouring down the Tower of London’s walls, will stay in place until the end of November, when the poppies will go on a tour of the country before being placed in a permanent exhibition at the Imperial War Museum in 2018.

Those who have bought the ceramic poppies will start to receive them in the post after they are plucked from the moat by a team of 8,000 people from Wednesday onwards.

Purchasers will be advised not to put them outside until at least the spring because of the risk of them cracking in frosts or freezing weather.

Costing £25 each, the poppies had sold out weeks into their sale and all net proceeds plus 10 per cent are to be shared between six service charities, including the Royal British Legion and Help for Heroes.

Paul Cummins, who created the Blood Swept Lands and Seas of Red installation, said last week that “it would be nice” to keep the poppies on display, but that the piece was intended to show the transience of human existence, and that “it belongs to the world now”.

The Government has pledged £500,000 to help fund the tour of the poppies, which will run until 2018, with added donations from the Backstage Trust and the Clore Duffield Foundation