The Ministry of Defence strengthened security around the radar station at Fylingdales in North Yorkshire but forgot to get planning permission, it has emerged.

Defence Minister Lewis Moonie has apologised to the national park authorities as he suspended work on improvements at the North York Moors site.

The base has been the target of protests by anti-nuclear demonstrators.

They are alarmed at the prospect that it could form part of the controversial national missile defence system favoured by US President George W Bush.

UK's missile support

Recently, protesters attacked the nearby Menwith Hill defence site twice in two days, prompting a safety review of installations.

Earlier this week Foreign Secretary Jack Straw gave the strongest indication yet that the UK supports the "Son of Star Wars" scheme.

And the MoD explicitly concedes that new work is to make life more difficult for protesters.

Existing fences are being increased in height with a new inner layer of razor wire.

There are new police posts and two miles of tarmac patrol road across the moor.