Plans to change National Minimum Wage legislation to allow employees to opt out and work for less money have been rejected by the Commons.
Christopher Chope told MPs that allowing adults who were struggling to find work to receive wages below the £5.93 hourly national rate could improve their chances of employment.
Opening second reading debate on his Employment Opportunities Bill on 17 June 2011, Mr Chope said current laws prevented British workers selling their labour "at a price of their own choosing".
But Labour's Denis MacShane said the bill was an "assault" on the minimum wage and should be renamed the "Increase in Working Poverty Bill".
He told MPs "this is the meanest, most miserable act from a mean and miserable party that hates the working people of this country."
The legislation would allow adult employees to opt out of receiving the minimum wage, would allow a lower "training wage" to be paid, and could see regional variations in the hourly rate paid to workers recommended by the Low Pay Commission.
It would also give asylum seekers the right to work in the UK while their applications were being considered.
Labour MP Tony Lloyd said the bill showed "what a rotten, nasty party the Conservative party are", and he warned the changes would allow bosses to exploit workers.
And Labour's Nick Smith, whose Blaenau Gwent constituency has one of the UK's highest rates of unemployment, described the plans as "a miserable attempt to gouge down wages of workers across our country".
Tory Philip Davies suggested that disabled people could overcome disadvantage in the workplace by being able to offer themselves for work at below the minimum wage.
He told MPs: "The people who are most disadvantaged by the national minimum wage are the most vulnerable in society.
"My concern about it is it prevents those people from being given the opportunity to get the first rung on the employment ladder."
Tory Edward Leigh challenged his remarks asking why a disabled person should work for less than the current £5.93 hourly rate. "It is not a lot of money, is it?" he asked.
Shadow business minister Gareth Thomas said Labour would not support the bill which "would drive a coach and horses" through national minimum wage legislation.
Low-paid workers would risk exploitation by "unscrupulous" employers wanting to undercut other businesses which paid the minimum wage, he added.
Winding up the debate, Business Minister Mark Prisk stressed the government was committed to the National Minimum Wage.
It gives protection to lower income workers and provides incentives to work, he said, but also helps business by "ensuring competition is based on the quality of goods and services provided and not on lowest priced based on potentially exploitative low rates of pay".
He rejected the idea of regional rates for minimum pay telling MPs it would be too complicated to divide the UK into different labour markets.
Mr Chope's bill was defeated by 5 votes to 33, a majority of 28. This mean it stands little chance of making further progress.