In an emotional section of his party conference speech, Lib Dem leader told party members of his experience in the Calais migrant camp.
"I met a 14 year-old boy who had broken both of his legs trying to board a lorry. He was in a wheelchair pushed by a boy who was 11. Both had lost their parents, both were alone," he said.
"I realised that the UK government was ignoring their humanity, it was just stuck in media management mode, following not leading.
"And the Government is still following the story. It’s just a rather different one. It’s the body of a three year old boy face-down in the surf."
The photograph of 3-year-old Alan Kurdi, found dead on a beach in Turkey, triggered a global outcry over the plight of refugees fleeing the civil war in Syria.
"What we’ve had from David Cameron is a careful calibration of what it will take to manage that story, the minimum effort for the maximum headlines," Farron said.
"And a policy which will not directly help a single one of the hundreds of thousands currently on the move across Europe. It’s pitiful and embarrassing and makes me so angry.
"Because I am proud to be British and I am proud of Britain’s values, so when Mr Cameron turns his back on the needy and turns his back on our neighbours. I want the world to know, he does not speak for me, he does not speak for us, he does not speak for Britain."