The 56-year-old has had a mixed managerial career, leading Gillingham, Brighton, Hull and Wycombe to promotions but having less illustrious spells at Leicester, Crystal Palace and Stevenage Borough.
He has also managed England Under-21s and been the country's senior caretaker boss for a friendly with Italy in 2000, when he made David Beckham England's captain for the first time.
Chairboys owner Steve Hayes told BBC Three Counties Radio: "We started the season reasonably well, but truthfully, six points from 33 is very worrying. We've been speaking for the last few weeks and now seemed the right time to make a decision.
"I think we need a change. [Peter's] body language in the last few weeks has not been great and he doesn't seem to be as happy as he was last year.
"I now want a manager that is going to be here for a good period of time, somebody that buys into our culture and vision as to what we want from the football club, and hopefully someone that is going to entertain the supporters.
"We do have somebody in mind and we have made an approach."
Meanwhile, Wycombe have released defender TJ Moncur from his contract.
The 22-year-old joined from Fulham in January but only made six appearances for the Chairboys.
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