The Government is remaining silent over claims that Chinese army computer hackers have broken into computer systems in Whitehall.
They have reportedly targeted the Foreign Office and caused the House of Commons computer to breakdown.
The Foreign Office has refused to discuss the claims, saying only: "We do not comment on security issues."
Andrew MacKinlay, a Labour member of the House of Commons Foreign Affairs Select Committee, said it seemed clear that the cyber-attacks had the acquiescence, at least, of the Chinese authorities.
He is urging Ministers to take a more robust stance with Beijing over the claims.
Mr MacKinlay insists that the public and Parliament have a right to be told if the UK is becoming the target of a phenomenon known as "patriotic hacking" - when computer experts use their skills to attack the vital networks of perceived enemies of their nation.
He said that his attempts to prise information from the Government about the scale of the problem had been stonewalled by Ministers including former foreign secretary Jack Straw, now Justice Secretary.
Mr MacKinlay said: "I am frustrated. This is clearly an area where the Government have decided not to comment. My questions were clearly unwelcome.
"The security and intelligence services and Foreign Office did not want this to come out into the public domain.
"This is happening against a backdrop where, on a whole range of foreign policy issues, the British Government is very weak. They seek to appease the Chinese. They should be more robust and indignant.
"We do not send out the right signal on this. Beijing know about it and, at the least, they acquiesce in it."
There was clearly a political motive behind the attacks, said Mr MacKinlay, who dismissed the idea that the hackers were simply "computer nerds" acting alone.
The most plausible theories on why the Chinese authorities might choose to foster patriotic hacking were either to test its potential as a weapon for use in future conflicts or simply to send a signal to other great powers that they have the capability to do so, he said.
Alex Neill, head of the Asia Security Programme at the Royal United Services Institute, said cyber-attacks by the Chinese had been taking place for at least four years.
He said that they reflected a new PLA doctrine of "pressure point warfare" - attacking specific nodes to leave an adversary paralysed.
If these Chinese commie scum want a cyber-war, we should be prepared to play them at their own game and see how they like being hacked. The same applies to Russia.