Use this tool to track real time tweeting intensity from Parliament. Remember that only about 2% to 5% of tweets are likely to have any kind of geo-tagged data.
Looking at the intensity of tweeting from the House of Commons on PMQS shows just how much twitter has become an integral tool for insiders and news gathers of power. If there was a time that tools like twitter gave an advantage to outside organisations, that time is clearly over. Pundits, wonks, and connected people are now using twitter as a key tool to control the discourse and organise their support.
Since PMQs are a TV event you are probably better off just looking at the semantic results for #PMQS Tweets about "PMQS"