Hacker and Bernard in “The Smoke Screen”

Hacker

He’s got to learn to come to heel. He’s got to learn to 'co-operate'.

Bernard

What do you mean 'co-operate'?

Hacker

I mean obey my commands! That's what 'co-operate' means when you're Prime Minister.

Bernard

Sir Humphrey's waiting to see you outside.

Hacker

Send him in, at once!

Bernard

Yes, Prime Minister. Your word is my 'co-operation'.