David Cameron has been accused of behaving like a "disturbing cocktail" of John Wayne and Alan Partridge.
The bizarre charge was levelled at the Prime Minister by Glenis Willmott, Labour's leader in the European Parliament.
Willmott attacked the way "Macho" Cameron was behaving over Europe.
The MEP also attacked UK Independence Party leader Nigel Farage for being a former City trader and "one of the breed who got us into financial mess in the first place".
She told the Labour Party conference in Brighton: "More and more, Britain has become fertile territory for the eurosceptics.
"With David Cameron and his ministers under threat from Ukip reacting by making up spurious stories like the supposed attack earlier this year on our British rebate by 'scheming' Europeans, though he knew full well that our rebate had long been agreed.
"And did you see what our macho Prime Minister said in Brussels at the time?
"He said, and I quote: 'In this town you have to be ready for an ambush at any time, and that means lock and load and have one up the spout, and be ready for it'.
"David Cameron - a disturbing cocktail of John Wayne and Alan Partridge. The mind boggles, doesn't it?"
Willmott called on Labour to go on the attack ahead of next year's European elections, which Farage is trying to turn into a de facto referendum on Britain's EU membership.
She said Labour must shift public opinion away from Tory and Ukip euroscepticism and said Europe should not be defined by "little Englander" myth and prejudice.
Candidates should campaign on issues such as bankers' bonuses, tax evasion, better working rights, climate change, consumer protection and equality, Willmott said.
She went on: "We don't have to accept a version of Europe defined by myth, prejudice and little Englander euroscepticism.
"We need to go on the attack in the lead up to next year's Euro elections."
The tiny dancer tennis move
Cameron shows the importance of doing an impression of a pencil to successfully hit the ball.
The 'flasher' face
The old 'here's my groin' move never fails to distract opponents
The stiff upper lip repost
Never at any point appear to be playing the game until, quick as a flash, you interject and pop the ball
The 'serve with your mouth' move
Dave perfects the perfect 'o' with his lips before either serving or catching the balls. Must be all those 'oh dears'.
The backwards butt shot
If you're PM, it's important never to make an arse of yourself.
The stiff upper lip move #2
Push head back into neck to reveal a total lack of chin.
Cameron strangles balls
The triumphant toilet move
Cameron shows he's crooked
..in his golf club. Cameron's advisors were keen to pick a competitor who would let him win.
The wide-eyed pass
The furrowed pirouette
The 'forget your bat' move
The 'pretending it's tennis' shot
No words really. But this is a school game of badminton
British Prime Minister David Cameron sma
British Prime Minister David Cameron smashes the shuttlecock as he plays badminton in the garden of 10 Downing central London March 28, 2012 with youth ambassadors of the School Games in an event organised for the visit of the International Olympic Committee (IOC) delegation lead by president Jacques Rogge. The IOC delegation started their last visit to London before the 2012 London Olympic Games. AFP PHOTO / POOL / CHRIS HELGREN (Photo credit should read CHRIS HELGREN/AFP/GettyImages)
The irish dancer
Britain's Prime Minister David Cameron plays badminton in the garden of 10 Downing Street in London, Wednesday March 28, 2012. Cameron is meeting with International Olympic Committee President Jacques Rogge and officials, amid the final inspection visit before the games by the IOC coordination commission. (AP Photo/Chris Helgren, Pool)
The morris dancer