A former Labour defence secretary has thrown his weight behind the Conservatives' ambitious £10billion 'iron dome' plan, insisting air defence must now be Britain's 'number one priority'.

Lord John Hutton accused Andy Burnham's Government of failing to 'step up to the plate' as mounting global tensions expose the UK's vulnerability to missile and drone attacks.

The Conservatives unveiled fresh details of the scheme, including proposals to extend protection to the Falkland Islands through what Shadow Defence Secretary James Cartlidge described as 'a fully integrated missile defence system capable of protecting our nation from drone attack'.

The Tories hung a Shahed 136 drone over the stage at their party conference to emphasise the threat to Britain.

Asked if the Britannia Shield should have cross-party support, Lord Hutton told Times Radio: 'I think it should. I mean, we've got significant gaps in our air defence capabilities. We should see this as a national number one priority.

'I don't have a problem with what the Conservatives are planning. We should welcome the fact someone is talking about this.'

Lord Hutton also laid into Labour over its record on defence. While defence spending has risen since the last election - from 2.3 to 2.7 per cent of GDP - the Government has failed to set out how it will reach targets such as 3 per cent of GDP by 2030 and the essential Nato benchmark of 3.5 per cent by 2035.

Lord Hutton said: 'I am not seeing the focus that I would like the Government to be giving it. I have no problem with [the PM] establishing a national care service. But should we do that at the expense of finding the resources to defend the country? Absolutely not.

'We're not stepping up to the plate on it [defence spending] right now.'

Shadow Defence Secretary James Cartlidge explained the party's Britannia Shield plan would extend to the Falkland Islands. A Conservative government would deploy the Rapid Sentry air defence system to deter Argentina's jets. The system is also adept at countering the threat posed by drones.

Mr Cartlidge has also committed the party to a sixfold increase in the Army's Sky Sabre air defence system, offering enhanced support to the South Atlantic and to Britain.

He told the conference: 'We will take whatever steps are necessary to stop anyone from thinking about an invasion. Because the Falklands are British and will always be British.'