The “menace” of Vladimir Putin will be impossible to confront if defence spending is cut, two former ministers have warned.

Labour’s Bob Ainsworth and Tory MP Sir Peter Luff have told the Mirror that Europe’s borders face a “real military threat” from war-mongering Russia.

Mr Ainsworth, a former Defence Secretary, and Sir Peter, a defence minister under David Cameron, insist defence spending should stay at 2% of GDP and say the danger is not confined to Russia, with the Argentines looking for buy fighter aircraft that could pose a risk to the Falkands.

In a joint warning to be published exclusively in Saturday's Daily Mirror, they say:

"Vladimir Putin’s aggression has put defence on the election agenda. Or it should have. Worryingly, all the major parties seem reluctant to take the hint.

"For the first time since the end of the Cold War, Europe faces a real military threat on its borders.

"Until Putin rattled his sabre, the direct threat to the UK was mainly from terrorists. His invasions of Crimea and eastern Ukraine have changed all that.

"Now we face a Russian leader who sees no real limit to his ambition. Look at his provocative flights of nuclear bombers off the coast of England.

"Putin leads the first major power since the Second World War to invade another state to gain territory. He claims to be the protector of all the Russian minorities in Central Europe.

"That means we must expect direct or, more likely, indirect attacks on Estonia, Latvia and Lithuania. This, after all, is a man whose greatest regret is the end of

the Soviet Union.

"Russia is not the only threat. The world is more dangerous than it has been for years. Instability in the Middle East exports terror. Argentina is getting Russian and Chinese help to rebuild its air force, which menaces the Falklands.

"China’s rising military power is a direct risk to many of our important trading partners.

"Despite all this, the major parties are trying to avoid talking about defence. Of the parties likely to win many seats at the election, only the Scottish Nationalists have a clear policy (though a disastrous one) – disarmament.

"Britain has rightly been urging its European allies in Nato to spend the organisation’s target of at least 2% of national income on defence. But while we meet that target this year, soon we will fall below it. Russian spending on defence climbs year on year, ours falls.

"No one likes paying for insurance – until they have to make a claim. Defence is a bit like that.

"But strong defence is more than insurance. It doesn’t just let you respond if you are attacked. It deters the attack in the first place. So it’s like insuring your house and putting big locks on all the doors.

"If ever there was a time to pay the premium for peace, this is it."

Their call comes as Mr Cameron faces a revolt by Tory backbenchers in the Commons next week over his plans to freeze the MoD budget. This would mean the UK breaking its pledge at last year’s NATO summit to keep spending at 2%.

There are mounting fears the Treasury will keep the budget at £36billion a year - an effective cut of 10% a year if it does not rise with inflation.

Former Tory cabinet minister David Jones added his voice to those alarmed at the cash squeeze. “If you look at the world landscape and all the threats we face I think it’s obvious that people want to be protected,” he said.

The Conservative chair of the Defence Select Committee Rory Stewart added: “As a major global power and a member of the UN security council we must keep our promise.

“Look at Iraq, Syria, Yemen, South Sudan and Ukraine and Russia too. We haven’t seen threats on this scale for 20 years,” he told the Times.

Mr Cameron has warned that further sanctions could be slapped on Russia if it failed to end its aggression in Ukraine.

The PM told the Wall Street Journal: “If Russia is going to rip up the rule book of the 21st century and destabilise a sovereign country, then the rest of the world should be prepared to say to Russia ‘well, you can’t rip up one part of the international rule book while still having access to international markets, international finance, international systems.”

The Ministry of Defence announced today that the UK is provide a further package of non-lethal military equipment worth £850,000 to the Ukrainian government.

Defence Secretary Michael Fallon said the package will include first aid kits, night vision goggles, helmets, GPS (global positioning system) units and “ruggedised” laptops.

Mr Fallon said: “This Government is committed to supporting Ukraine’s sovereignty, independence and territorial integrity. As a result of their prolonged engagement in this conflict, the Ukrainians face a serious shortage of basic equipment, and have requested help.

He added: “Russia’s illegal annexation of Crimea and its destabilising activities in eastern Ukraine, including direct military support to the separatists, have demonstrated its disregard for international law.”

Labour today said it would save £60 million a year from the MoD budget by tackling waste and bringing down the numbers of Navy top-brass.

This would include £29million a year from reducing weapon and kit stockpiles. And £32million a year from reducing officer ranks in the Royal Navy.

Shadow Defence Secretary Vernon Coaker said: “We know that defence is the first concern of any government and therefore it must be a priority for any party which aspires to govern.

“But we also know that in these challenging financial times, we will have to make tough decisions.”

“This document shows that Labour is committed to making appropriate efficiencies in the Defence budget in order to maximise frontline capabilities and ensure that the UK’s Armed Forces are put on a sustainable footing.”