Devon MPs are calling for an urgent meeting with the new owners of Devonport Dockyard to discuss the site's future.
Devonport refuels and refits the Royal Navy's nuclear submarines
Engineering group Babcock International is buying the naval dockyard in Plymouth in a £350m deal.
Devonport maintains, upgrades and fuels Royal Navy submarines, and with 4,800 staff is a major regional employer.
South Devon MP Gary Streeter said they had concerns about Devonport's workload. "The jury is still out."
Babcock maintains the Rosyth and Faslane submarine bases in Scotland.
It is buying Devonport Management Limited (DML) from a consortium which includes Kellogg Brown & Root, Balfour Beatty and Weir Group.
The group said the "combined strength of Babcock and DML will yield significant strategic and financial benefits to the Ministry of Defence".
Mr Streeter is seeking to hold talks with Babcock together with Plymouth Labour MPs Alison Seabeck and Linda Gilroy.
Mrs Seabeck, Labour MP for Plymouth Devonport, said: "We need to find out exactly what the company are proposing.
"Potentially it could be good for DML. It could bring more security over a longer period."
She said the dockyard had been going through a period of "peaks and troughs" in output and she would be pressing for the new owners to ensure there was an on-going skills base at the dockyard.
"Babock does fully understand this need because of their background and shipping experience."
Union representatives were unavailable for comment.
DML supports nuclear submarines and surface vessels for the Royal Navy and has controlled the Plymouth dockyard since 1997.