Ed Miliband is personally to blame for the crisis in Ukraine, senior Conservatives claimed last night.
Allies to David Cameron and George Osborne made the extraordinary claim after Russian president Vladimir Putin authorised military action within the country.
There is a "Direct link between Miliband's cynical vote against Syria motion & Russia's actions on Ukraine," Treasury minister and close aide to the chancellor, Sajid Javid tweeted, adding that this made the Labour leader "Completely unfit to lead Britain".
He was joined by planning minister and close ally to the prime minister, Nick Boles who said that Miliband's "weakness" had caused the conflict.
The "PM was right to urge Parliament to stand up to Putin and punish Assad's use of chemical weapons," Boles tweeted. "Look where Miliband's weakness has led us."
The Labour leader's decision to oppose military action in Syria led to one of David Cameron's worst defeats as prime minister and stalled hopes of intervention against president Assad.
Some analysts believe the failure to act against one of Putin's allies, has emboldened the Russian president.
The latest attack on Miliband comes as the Conservatives MPs have been urged to "throw the kitchen sink" at the Labour leader.
Fears have grown in Tory circles, as the return of economic growth is failing to dent the Labour party's lead.
Conservative campaign manager Lynton Crosby is thought to favour a lengthy personal assault on Miliband, designed to "Kinnockise" the Labour leader.
Former Labour leader Neil Kinnock maintained a large poll lead over the Conservatives, but lost the 1992 general election after a sustained assault from the Conservatives and supporting newspapers.
Javid's and Boles' attack on Miliband was met with consternation last night, with many Twitter users pointing out that a large number of Conservative MPs also voted against intervention in Syria.
Former Labour defence spokesperson and shadow development secretary Jim Murphy described their claims as "desperate".
Ed Miliband also dismissed the claims today, telling the Guardian that they were "complete nonsense".