UK must keep Trident nuclear deterrent - David Cameron

The UK would be "foolish" to abandon Trident in the face of the potential threat of nuclear attack from North Korea and Iran, David Cameron has said.

Writing in the Daily Telegraph, he said the country still needed the "ultimate weapon of defence".

The prime minister said the nuclear danger had "increased" since the end of the Cold War.

The Lib Dems want the UK to explore a cheaper alternative to the Tories' £20bn plan to replace Trident.

Brian Taylor reports.