As navies seek to counter submarines and protect cables, startups and big defence companies fight to lead market

Flying drones used during the Ukraine war have changed land battle tactics for ever. Now the same thing appears to be happening under the sea.

Navies around the world are racing to add autonomous submarines. The UK’s Royal Navy is planning a fleet of underwater uncrewed vehicles (UUVs) which will, for the first time, take a leading role in tracking submarines and protecting undersea cables and pipelines. Australia has committed to spending $1.7bn (£1.3bn) on “Ghost Shark” submarines to counter Chinese submarines. The huge US Navy is spending billions on several UUV projects, including one already in use that can be launched from nuclear submarines.

As they struggle with the cost of living, people weigh up whether Rachel Reeves’s measures will help them

• What the budget means for people on a range of incomes

• Budget calculator: find out if you are better or worse off

For Brett and Maria MacDonald, the cost of living has been biting this year, from rising mortgage payments to childcare fees. Living in London with two young children and no extended family nearby, the pair are juggling work with parenting.