An IT graduate who posted messages on an Islamic extremist website calling on Muslims to attack British MPs who voted in favour of the war in Iraq has been jailed for 12 years.
Bilal Zaheer Ahmad, 24, posted the vile threat on the US-based RevolutionMuslim.com website a day after a Muslim woman had been jailed for trying to murder a senior Labour MP, Bristol Crown Court heard.
Mr Justice Royce jailed Ahmad for 12 years with an additional five years' extended period on licence.
The judge told him: "Whatever our views on the Iraq war, we are a democracy. You purport to be a British citizen but what you stand for is totally alien to what we stand for in our country.
"You became a viper in our midst willing to go to as far as possible to strike at the heart of our system."
Mr Justice Royce told Ahmad his views were "corrosively dangerous" and that he had attempted to strike at the heart of British democracy.
"Politicians are often faced with difficult decisions. They don't always get it right," the judge said.
"They have to face up to serious criticism on occasions as part of the democratic process. The same can be said for bankers, press barons and judges.
"It is important MPs can hold constituency surgeries without the threat of someone pulling out a knife and trying to kill them.
"You were intent on striking at the heart of our democracy and if our politicians are to be at risk from those like you, then the message must go out loud and clear that this country will not be tolerate such threats to its democratic processes."