Two Sea Kings are based at RAF Boulmer
Round-the-clock helicopter rescue cover is to resume from RAF Boulmer in Northumberland, the Ministry of Defence (MoD) has confirmed.
The airbase's two Sea Kings have been grounded at night for the last four weeks due to a shortage of equipment and crews.
Rescue cover during this period has been provided by other UK bases.
The suspension of night operations, which was originally scheduled to last for a week, will now resume on Sunday.
The base's two Sea Kings typically carry out rescues in north-east England, south-east Scotland and the Lake District.
Under government plans, cover from Boulmer will be reduced to "daytime only" from 2012, when a private consortium takes over the UK's helicopter rescue service.
Sir Alan Beith, the Lib Dem MP for Berwick, said he feared the long-term plan could significantly reduce response times.
He said: "I'm very glad the 24-hour operation is back but it remains vulnerable because they are short of air crew and they also have problems with the now pretty old Sea King helicopters.
"My main worry is that this is part of the long-term plan that it should go to 12-hour operation in the future.
"It is over-stretching a service which is tremendously good. Finding it cut back in this way is distressing."
An MoD spokesman said bases throughout the UK provided "interlocking cover."
He said: "UK Search and Rescue (SAR) helicopter units operate a 24-hour service.
"If a helicopter is either committed to an operation, unserviceable or operating at a reduced capability for any reason, an adjacent SAR unit will provide the necessary overlapping cover."