A network of Republican lawmakers and their rightwing corporate funders are battling behind closed doors to block minimum wage increases in cities across the US, in a step-by-step counter-attack that could cut back the incomes of millions of Americans despite an economic upswing.

According to strategic details obtained by the Guardian, the American Legislative Exchange Council (Alec) – along with its localised sister organization, ACCE – is trying to prevent elected city representatives from raising the minimum wage to levels above those set by their states. The group has launched an aggressive dual-track mission that combines legislation and litigation in what Alec calls a “new battleground” over worker compensation.

The anti-wage increase moves come as Walmart, a former corporate member of the Alec network and the largest private employer in the US, responded to a barrage of criticism over the company’s low wages this week by agreeing to raise its base rate to at least $9 an hour for about 40% of its employees. The hike will marginally improve the earnings of about 500,000 Walmart workers, though it falls far short of the $15 per hour that staff – and labor advocates in cities across the country – have been demanding.

Alec’s plan to oppose minimum wage increases at the local level was set out in a recent meeting in Washington DC that brought together Republican legislators with several large corporate backers. The meeting was closed to journalists, but the Guardian has obtained details of the discussion from participants.

Cara Sullivan, who heads Alec’s commerce, insurance and economic development taskforce, told the meeting that corporate America was facing an “onslaught” of bids to raise the minimum wage at all levels of government. “Perhaps the biggest threat comes from the local level. We are seeing a number of localities that have increased their minimum wage,” she said, according to the accounts.

With an increasingly national and political focus on the inequality chasm between the so-called “1%” and a middle class that continues to struggle against wage stagnation, individual US cities have been forcing the pace of change by setting their own progressive standards. In a historic ballot initiative last year, Seattle voters approved a $15 per hour minimum. As other cities follow close behind – San Francisco approved a similar rise, Chicago has introduced a target of $13 an hour, and other cities including Los Angeles and San Diego have pressed phased increases – the trend is now even touching the likes of Walmart.

Alec’s response, Sullivan went on to explain at the meeting, is to frame and then lobby for model legislation in state assemblies across the country. She said that so far 12 states, most recently Oklahoma, have submitted anti-increase legislation based on the rightwing lobbyists’ language. “Our solution that Alec has passed is state legislation that pre-empts the polities from within the state from raising the minimum wage higher than state level,” she told the meeting.

Walmart has agreed to raise its base rate to at least $9 an hour. Photograph: Scott Olson/Getty Images

A copy of a model bill, called the “living wage mandate preemption act”, is posted on Alec’s website. Most recently approved by the Alec board in 2013, it provides for the repeal of any minimum wage provisions introduced by local elected bodies within a state, claiming that increases “threaten many businesses with a loss of employees”.

Since it was formed in the 1970s, Alec has grown into one of the most influential lobbying bodies in the US. It acts as a form of dating service, bringing together large corporations – such as the oil empire of the rightwing tycoons the Koch brothers – with state legislators who can introduce new legislation, sometimes copied whole-cloth, that is favorable to such businesses. Alec’s local branch, ACCE, seeks to play the same role with blanketing laws at the city and county level.

The tone of the discussion at the Alec/ACCE meeting in December suggests growing alarm on the part of big businesses and their Republican allies over recent wage hikes in several major American cities.

Heightening the concern among rightwing groups is the sense that they are losing the argument: in several states, including in conservative parts of the country such as South Dakota and Arkansas, voters backed minimum wage initiatives by large margins last November. In a speech on Friday, Barack Obama said the hikes represented “perhaps the single most hopeful sign for middle-class families in a very long time”, and an Associated Press-GfK poll released this week found that six out of 10 Americans want a higher minimum wage.

“This is a policy that is very popular,” Sullivan conceded in her address to the Alec/ACCE meeting.

At the meeting, speakers described bringing lawsuits to try and stop cities from introducing pay increases. Dean Heyl, a lobbyist with the International Franchise Association – which represents 1,400 franchises, including some of America’s biggest such as Dunkin’ Donuts and Subway – said his organization had filed a legal challenge to Seattle’s hike.

Heyl presented the battle as a partisan political struggle pitting unions against employers: “I’m a Republican. We’re seeing the unions looking at the cities as their next target – we beat them on the federal level, we beat them on the state level. But the cities are much tougher, because there are more of them.”

Brian Crawford, a senior executive at the American Hotel and Lodging Association, told participants that his group was preparing litigation in Los Angeles and other cities to block wage increases. “Hopefully there’s no press in here,” he said.

Crawford also urged conservatives to launch populist campaigns against wage increases by adopting the mantra that higher pay hurts ordinary Americans. It was crucial, he said at the meeting, to have “the right face, and that’s one of the things we’re focusing on… Not the Hyatts, not the Hiltons, not the Marriotts, but the small business people, telling their story about the American Dream – the independently owned Holiday Inn, owned by an Asian-American who came to this country, put all their life-savings into it, and now they’re going to lose this business because they can’t afford a $15 wage.”

The lobbying executive added: “We have a lot of resources; we have the studies, the economic data. And we have the real-life stories that we can put out there. The key component is the PR.”

Crawford likened the conservative battle against city wage increases to a game of Whack-a-Mole: “We’re trying to beat them down when they pop up.”

The meeting was attended by Steve Arnold, a progressive elected representative from Fitchburg in Wisconsin. Arnold said the strategy presented to the room by Alec aimed to “make sure that corporate profits go to the management and the shareholders while the workers, who are the profit creators, lose out”.

Jeb Bush speaks at the American Legislative Exchange Council’s 40th annual meeting in August 2013. Photograph: M Spencer Green/AP

Brendan Fischer, general counsel for the Center for Media and Democracy, which monitors the activities of Alec, said the discussion exposed that the conservative commitment to local decision-making was serving as cover for lobbyists who invented legislation for businesses.

“They are prepared to eliminate local control to support the interests of their corporate funders,” Fischer said. “Minimum wage increases in cities like Seattle are starting to force companies like Walmart to respond with their own higher wages – and that’s precisely what Alec is trying to stop.”

Alec’s overarching message, as outlined in policy papers, is that minimum wage increases are bad for the economy. Sullivan told the December gathering that “the minimum wage favors those who already have jobs at the expense of the unemployed.”

But a large body of economic research has discredited such assumptions. Multiple studies have over many years, comparing cross-border jurisdictions with and without minimum wage provisions, have found that employment expands in line with wages.

“This is probably the most studied topic in labor economics,” said David Cooper, an economic analyst at the Economic Policy Institute. “The notion that a higher minimum wage will lead to job losses just isn’t borne out by the research.”

Walmart was a leading and high-paying member of Alec for many years until May 2012, when the company withdrew after the network came under fire for having propagated “stand-your-ground” gun laws around the country. The legislation became controversial in the wake of the shooting in Florida of the unarmed black teenager Trayvon Martin – Walmart had chaired Alec’s criminal justice taskforce that conceived the “stand-your-ground” model bill.

An Alec spokesperson, Wilhelm Meierling, told the Guardian on Friday that Walmart’s decision to improve its remuneration vindicated the network’s belief that the market – and not the government – should drive wage increases.

“Walmart acknowledged they needed to do more to compete in the employee marketplace and retain top talent,” he said. “Its actions are exactly what Alec would call for.”