London, Nov 5 : Britain could be left with no nuclear deterrent for the first time in 40 years, Whitehall's spending watchdog has warned.
The National Audit Office said even the smallest delay in building our new 20billion pound fleet of nuclear subs could leave us completely unprotected.
It would be the first time since 1968 that the UK did not have its crucial nuclear shield. ur existing fleet of four Vanguard nuke subs will come to the end of their life in the early 2020s, The Sun reported.
But their replacements will not be ready until 2024. In a hard-hitting report the National Audit Office said building the subs must be started by 2014 at the latest.
They must then be completed by 2022 to allow for two years of rigorous trials and tests before they go into service. NAO chief Tim Banfield warned the timescale was so tight that any hold-ups could be disastrous.
"There is a real risk that we will not be able to provide the continuous nuclear deterrent which we have had every day since 1968."
He said the lifespan of the Vanguard subs has already been extended by five years - leaving virtually no room for manoeuvre.
And there is another key problem - making sure the new generation of American Trident nuclear missiles actually fit inside the new subs. Britain will build the vessels without knowing how big the US missiles will be.
The Audit Office report also stressed that the Ministry of Defence has an appalling record of delays and spiralling costs in major projects.
Britain's new Astute submarines are nearly three-and-a-half years late and the cost has spiralled from 2.5billion pound to 3.7billion pound.