>Do/did they really hit each other?

These days, more often outside Parliament than in. The Deputy Prime Minister had "altercation" with an egg-throwing member of the public during the recent election campaign. http://politics.guardian.co.uk/gall/0,9352,492489,00.html

As Mr Bingley points out, the MPs (Members of Parliament) are not two sword lengths apart for nothing. A memorable incident was in 1976 when Michael "Tarzan" Hesletine, furiously grabbed the mace and held it above his head (have you seen the size of it?) in response to members of the opposition singing "the red flag".
http://news6.thdo.bbc.co.uk/hi/english/uk_politics/a-z_of_parliament/m-o/newsid_82000/82544.stm
I had thought that Dennis Skinner had also grabbed the mace (and possibly hit someone) but I can't find it in a report.

The House of Lords woke up from its customary slumber one day in 1987 when lesbian activists abseiled into the House of Lords from the public gallery shouting "Lesbians are angry" in protest about anti-gay legislation.