The conservative lobbying group Alec has been behind a major push against the pay rates of low-wage American workers by sponsoring or supporting scores of new laws aimed at weakening their protections, a new survey has found.

Since 2011, politicians backed by the American Legislative Exchange Council, which has hit the headlines for previous campaigns on voting rights and gun laws, have introduced 67 different laws in 25 different states on the issue.

The proposed laws are generally aimed at reducing minimum wage levels, weakening overtime protection or stopping the local creation of minimum wage laws in cities or states. Using language similar to "model bill" templates drafted by Alec, they were put forward by local politicians who are almost always Republican and affiliated with the powerful conservative group.

Critics say Alec is backed by powerful corporate groups that are seeking to draft legislation that serves their business interests. "Public scrutiny is the best weapon against their agenda," said Jack Temple, a policy analyst at the National Employment Law Project, which advocates on workers' rights and drew up the report.

Eleven of the 67 bills eventually became law. They included an Arizona bill weakening public sector wage contracts, an Idaho bill preventing state and local government from adopting some wage laws and New Hampshire legislation that repealed that state's minimum wage law.

The phenomenon has come as the US economy struggles to recover from the impact of the Great Recession. Even though corporate profits are high and the stock market has soared to new record levels, job growth has been tepid and real wages largely stagnant as the economy has shifted in a low-wage direction. One study has found that around 60% of jobs lost during the recession were middle or high wage while some 58% of new jobs in the recovery have been in low-wage sectors.

"With real wages for low wage workers already declining in the post-recession recovery, the last thing America's workers need is frontal assault on pay and overall compensation by state legislatures," said Christine Owens, Nelp's executive director.

Indeed, President Barack Obama called for a rise in the minimum wage in his state of the union address in January, though many experts see such a move as unlikely to pass Congress. Alec, meanwhile, denies it is attacking workers' rights. "I feel that the Nelp report unfairly casts Alec as a suppressor or oppressor of American workers. We are not against employees of companies. Rather, we believe the market should dictate wages," said an Alec spokesman.

Alec has come under fire several times in recent years for its campaigns. After drawing serious criticism from civil rights groups for its backing of stand-your-ground gun laws and also voter ID legislation, Alec decided last year to abandon campaigning on social policy issues in favour of concentrating on economic policies.