The fight to keep 24-hour search and rescue cover at RAF Chivenor has been taken to the Senedd by Pembrokeshire's Assembly Members.

Both Angela Burns and Paul Davies have grave concerns about the plans to reduce the operating hours of the base – from which the Sea King helicopters fly – to daytime only.

If the cuts go ahead then any nighttime emergency off the coast of Pembrokeshire would have to be covered by helicopters from either RAF Culdrose in Cornwall, RAF Valley in North Wales and even Lee on Solent in Hampshire.

"Pembrokeshire has already seen its emergency response times for air-sea rescue lengthen with the removal of Sea Kings from Brawdy in 1992," said Mr Davies.

"If someone is hypothermic then the extra half an hour it will take a helicopter to fly from Culdrose could be the difference between life and death."

Mrs Burns is now tabling a written question to the Welsh Assembly Government raising the issue.

"I want to know whether they have had any discussions with the Ministry of Defence about these proposals and where the cover will come from if the Culdrose or Valley choppers are already tied up on operations," she said.

The MOD is planning to cut cover at Chivenor from 24 hours to 12 hours from 2012. But as Mrs Burns points out, it is light for 18 hours a day during the summer.

"This is also the busiest time for emergency crews in terms of call outs to pleasure craft in distress," she said.

"What happens if someone needs help at 8pm on an August evening – it may be classified as "nighttime" by the MOD penpushers but it's still light and people may still be sailing and surfing."