I remember listening to one of the authors describe how they got the inspiration for the programme from the following true story.
There was a British Member of Parliament whose party were in opposition. He felt strongly about a particular issue and decided to campaign to try and get the government to change their policy. He made speeches, wrote articles etc. He collected signatures and presented a petition to Parliament.
Then there was an election. The M.P. won and so did his party. They formed the Government. The M.P. was appointed to the Government, to the Ministry responsible for policy related to his petition. Soon after appointment he rejected his own petition.
This made Jay and Lynn realise that there must be some hidden hand manipulating political events, somebody who never appeared in public but was able to control what happened. In 'Yes Minister' the hidden hand was the devious Sir Humphrey Appleby.