President Barack Obama openly mocked Republican rival Mitt Romney with a barbed attack on his pledge to "fix Washington from the inside".

Speaking at a rally in Virginia, Mr Obama sparked bursts of raucous laughter from the crowd as he lampooned the presidential hopeful with a volley of quips.

"Now, for some reason my opponent got really excited," he told supporters. "He rewrote his speech real quick.

"He stood up at a rally, proudly declared, 'I'll get the job done from the inside.'

"What kind of inside job is he talking about? Is it the job of rubber-stamping the top-down, you're-on-your-own agenda of this Republican Congress? Because if it is, we don't want it.

"If it's the job of letting oil companies run our energy policy, we don't want it. If it's the job of outsources writing our tax code, we don't want it.

"If it's the job of letting politicians decide who you can marry, or control the health care choices that women should be able to make for themselves, we'll take a pass. We don't want an inside job in Washington."