Sefton Central Labour MP Bill Esterson said the government's Beecroft report was "another attack on working people".
Venture-capitalist and major Tory Party donor Adrian Beecroft was commissioned by close friend David Cameron to produce a plan to make it easier for companies to fire staff.
Beecroft is an investor in payday loans Wonga.com.
Bill Esterson said David Cameron was "looking after the interests of his rich friends at the expense of hard working people".
Bill said: "The Beecroft report is an attack on working people. It strips away any protection working people have in the workplace and gives companies the right to 'fire at will'.
"While David Cameron erodes the rights of workers which have been hard fought for over a century and which will see employees' pay being attacked by big businesses hell bent on making ever larger profits at the expense of staff, so Adrian Beecroft's day job will benefit as people are forced to turn to legal high street loan sharks like Wonga.com to make ends met.
"This report is a disgrace and David Cameron and Nick Clegg should consign it and not our hardworking people to the dustbin.
"But this is just another example of this Tory-Lib Dem government looking after the rich at the expense of everyone else. It's one rule for the wealthy, especially for Cameron, Clegg and their friends but another rule for the rest. The government just don't get it. This is wrong for working people, wrong for the economy and wrong for the country."
Bill today called for tighter regulations to control how much interest payday loan companies like Wonga.com can charge people.
Bill said: "I am deeply concerned that someone like Adrian Beecroft has the ear of David Cameron. I am more concerned that David Cameron appears to be listening to him.
"Payday loan companies like Wonga.com take advantage of people who need help the most.
"Instead of making it easier to fire people as Beecroft recommends, this government should be making it easier for companies to hire people.
"Only then will we see the economy turn around and get us out of this Tory-Lib Dem-created recession."