A consortium led by the Babcock International defense group won the competition to build new frigates for the Royal Navy and secured hundreds of jobs at British shipyards, including Northern Ireland and Scotland.

The deal brings Belfast's Harland & Wolff, the builder of the Titanic, who joined the administration last month, a potential lifeline. It will also bring a much-needed boost to Ferguson Marine Engineering, which is expected to be taken over by the Scottish government after the collapse in August. Both shipyards are members of the Babcock consortium.

Boris Johnson, to name his preferred bidder on Thursday, hopes the announcement will undermine his reputation as a strong supporter of the UK.

The British Prime Minister promised to bring shipbuilding home. He said Britain is "an outward-oriented island nation, and we need a shipbuilding industry and a Royal Navy that reflect the importance of the seas for our safety and prosperity." However, warships were always built in Britain.

Stephen Kerr, Stirling's Conservative MP, said the message was "absolutely fantastic" for Scotland and would create "new jobs for young Scots".

Mr. Johnson struggled to reconcile his party's focus on the union with his quest for a tough Brexit, underscored by the resignation of Scottish conservative leader Ruth Davidson last month.

Party insiders said that this year's election would lose the majority of Scottish MPs. The Babcock news is likely to be cited by Mr Johnson during a campaign as an example of how conservatives invest in cross-union enterprises.

The Scottish National Party has accused the British government of breaking the promises made prior to the 2014 independence referendum by reducing the number of sophisticated type 26 frigates to be built by BAE Systems in Glasgow.

The competition for the construction of five frigates of type 31e for £ 1.25 billion started in February 2017 but concerns were expressed about the low price budget. Ships intended for security, prohibition and other maritime tasks will replace Type 23. The first ship will be delivered in 2023.

The unions had previously warned against losing jobs at Babcock's Rosyth shipyard if they could not win the contest. Work on the construction of the two aircraft carriers of the Navy came to an end.

The Babcock consortium includes Thales and H & W and Ferguson. According to the original proposal, it was planned to assemble the ships in Rosyth with "blocks" built by H & W and Ferguson. It remained unclear whether the role of H & W and Ferguson in the consortium would be affected by their situation.

Johnson will also use the announcement as part of a broader pledge to revive British shipbuilding and strengthen the Royal Navy, which was scrutinized following Iran's acquisition of a British tanker.

Mr. Johnson appoints Ben Wallace, Secretary of Defense, as shipbuilding tsar, with the task of working across government to improve the "shipbuilding company".

The Type 31 program is central to the UK's naval naval strategy and is itself a response to an independent review in 2016 by industrialist John Parker. It was recommended that ships be constructed taking into account export and cooperation between shipbuilders, reversing any policy that had made BAE Systems the main supplier of naval vessels.

The Babcock consortium won against the competition of a BAE-led and Atlas Elektronik UK-led team.

Babcock declined to comment.