if you say it's high time that something happened, you mean that it should already have been done.

Her parents decided it was high time she started paying some rent.

It's high time that nurses were given better pay and conditions. (often + that)

• the pot calling the kettle black
• the power behind the throne
• the powers that be
• the primrose path
• the prodigal son
• the promised land
• the proof of the pudding .
• the proof of the pudding
• the proof of the pudding is in the eating
• the proof of the pudding is in the eating.
• the pros and cons
• the rank and file
• the real McCoy
• there and then
• There are no flies on .
• There are no flies on someone.
• There are plenty more where that came from.
• There are plenty more where they came from.
• There but for the grace of God .
• There but for the grace of God go I.
• Thereby hangs a tale.
• the received wisdom
• the red-carpet treatment
• the red-light district
• Therein hangs a tale.