Tests at Horatia House and Leamington House, after the Grenfell fire, revealed a fire risk.
Plaques Honour Cockleshell Heroes
Blue plaques have been unveiled on the houses in Southsea used by the Cockleshell Heroes as they trained for their daring mission 70 years ago.
Portsmouth City Council and the Royal Marines Association organised the plaques to mark the anniversary of the raid on Nazi-occupied Bordeaux in December 1942.
The Royal Marines trained to use canoes - the cockleshells - to access the strategically important French port which was used to supply the German army.
They were taken to the Bay of Biscay on the submarine HMS Tuna on December 7 before they paddled about 75 miles along the Gironde River until they could sneak into the port of Bordeaux and plant limpet mines on the merchant ships docked there.
Only one of the six two-man canoes made it to the port, with the others either capsizing or being captured before being executed by the Germans.
The mission, which sank one ship and severely damaged four others, was praised by Winston Churchill who said it helped shorten the war by six months.
The plaques were unveiled at houses in Spencer Road and Worthing Road in Southsea.
Ron Locke, chairman of the RMA southern region, said:
''It is important for young people to know and learn about the bravery that these men showed in this daring raid.
''The blue plaques are good as they draw attention to the fact that these were houses of importance during the Second World War.''
The unveiling of the plaques is to be followed on November 4 by a public ceremony marking the 70th anniversary of the raid.
This will see the RMA place a memorial near the Royal Marines Museum, Portsmouth, with Lord Ashdown as guest of honour and relatives of the heroes attending.
Council Backs Plans To Transform Bournemouth’s Winter Gardens Car Park.
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It'll have Q&A sessions in all 19 of its blocks - and a programme to install sprinklers starts soon.
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