The number of job losses announced this week in the defence industry could be higher than first reports have suggested.
The total number of shipbuilding positions being cut as a result of a declining order book could be around 1700.
The announcement is expected on Thursday and will be made by the defence contractor BAE Systems.
ITV News understands the majority of the losses will be made on the south coast: not in Plymouth but in Portsmouth.
MPs in the city have been told to expect bad news on Thursday.
Portsmouth is the home of the Royal Navy but the job losses will be in the private sector - not in the military.
The order book for new ships has dried up and there is little work from foreign governments or other companies to offset the lack in demand from Britain's Ministry of Defence.
Portsmouth has constructed parts of the two new aircraft carriers currently being assembled in Rosyth.
However, the go ahead for new Type 26 Global Combat Ships has not yet been given.
A dozen are due to be built to replace the Royal Navy's fleet of Type 23 frigates.
There will be job losses too at the company's Scottish bases.
But the BAE Systems' shipyards at Govan and Scotstoun on the River Clyde are likely to be hit less hard than the base in Hampshire.