Shipyard workers on the Clyde have been "let down and betrayed" by the UK Government, according to Nicola Sturgeon.

The First Minister accused the Conservatives of pulling back from a pledge that the yards in Glasgow would be a "frigate factory" for the Royal Navy.

Her criticism came after Theresa May's government announced plans for work on new warships to be split up across different sites.

Defence secretary Michael Fallon said the first batch of five new Type 31e frigates could be built in blocks across several British shipyards and then assembled at a central hub.

The ships, and the eight new Type 26 frigates that are being built in Glasgow, will replace part of the Navy fleet which is being phased out.

In the run up to the 2014 independence referendum, unionist politicians stressed that staying in the UK was necessary to secure the future of Scotland's shipbuilding industry.

The new Type 31e frigates are due to be in service by 2023 and their cost will be capped at a maximum of £250m each - with shipyards being encouraged to ensure the vessel is competitive on the global market.

The plans form part of a new national shipbuilding strategy which accepts the recommendations of an independent report into the industry by Sir John Parker, the chairman of mining giant Anglo American.

In November, Sir John said the Navy fleet was being depleted by a "vicious cycle" of old ships retained beyond their sell-by date, and found that the procurement of naval ships took too long from concept to delivery compared with other industries.

The defence secretary also stressed the BAE Systems yard at Govan would be able to bid for the new contract.