Madison, Wisconsin (CNN) -- Embattled Republican Gov. Scott Walker fired back at opponents of a budget bill that would increase the costs of benefits to public employees and curb their collective bargaining rights, describing in a written statement how current agreements give too much power to unions.
Walker highlighted questionable uses of taxpayer money as advocated by unions, noting a Milwaukee teachers union that last summer tried to negotiate health insurance using taxpayer dollars to pay for erectile dysfunction pills.
Unions have argued that collective bargaining -- a process of negotiations meant to regulate working conditions -- has instead served to protect wages and health care, enforce workplace safety and serve as a means to arbitrate employee grievances.
The bills' supporters say union contracts have hamstrung efforts to address the state's swelling deficit.
Some 385,000 workers belonged to a union in Wisconsin, accounting for more than 15 percent of wage and salary workers in 2009, according to the U.S. Bureau of Labor and Statistics.
The budget repair bill proposed by Walker to address a $137 million shortfall through June 30 would increase contributions of state workers to their pensions and health insurance benefits. It also requires collective bargaining units to conduct annual votes to maintain certification, a costly procedure, and eliminates the right of unions to have dues deducted from worker paychecks.
Walker says the measures are needed to head off a $3.6 billion budget shortfall by 2013 that could result in thousands of layoffs.
Meanwhile, the number of protesters gathering daily in Madison -- it exceeded 50,000 on Saturday -- had dwindled by Monday as a winter weather advisory was in effect for much of the state.
Guitarist Tom Morello of Rage Against the Machine planned to play for the remaining protesters a day after Walker signaled no retreat on the measure. Supporters call the bill vital, but opponents label it union-busting.
"History is happening in the streets of Madison, Wisconsin and I'm going to be there," said a statement by Morello, who will perform in his solo identity as The Nightwatchman.
Calling the proposed budget law "unjust," Morello said he will join "teachers, students, firefighters, policemen, Green Bay Packers, nurses, steel workers, construction workers and religious groups that are filling the streets to protest."
He referred to Walker as "the Mubarak of the Midwest" in reference to the Egyptian leader ousted by popular protest, and accused the governor and unnamed corporate allies of trying to "rob American workers of their fundamental rights."
Last week, 14 Democratic state senators essentially boycotted the legislature and went to Illinois to prevent a quorum from passing the bill. The measure's opponents say they won't allow a vote unless Walker negotiates on the plan to eliminate collective bargaining rights for everything but wages.
To break the impasse, Republicans need just a single Democrat to meet the mandatory quorum of 20 lawmakers to vote on fiscal issues.
Democrats need to draw at least three Republican lawmakers to the block the bill or otherwise renegotiate the proposal.
Walker rejected such a deal Sunday in an interview on "FOX News Sunday."
He called the Democratic complaint of union-busting "a red herring" and said significant changes were needed for budgetary reasons, but that powerful public employee unions had been able to block the necessary adjustments.
"If we're going to ask our state and local workers who are doing a great job to pay a little bit more, to sacrifice, to help to balance this budget, we should also give them the flexibility saying that for those members, for those workers, who don't want to be a part of the union, if you don't want that deduction each month out of the paycheck, they should be able to get that $500, $600 or in some cases, $1,000 back that they can apply for their health care and their pension contribution," Walker said.
U.S. Sen. Dick Durbin, D-Illinois, disagreed, saying that anyone who thinks the bill is only about money and the budget would also think that the Rev. Martin Luther King Jr. was working only for African-Americans to have access to restaurants.
"There's a much bigger issue at stake here," Durbin said on the NBC program "Meet the Press," adding that Walker "is not setting out just to fix a budget; he's setting out to break a union."
Rep. Paul Ryan, R-Wisconsin, said the events in his state are a microcosm of the budget pressure felt by governors throughout the country.
"It just shows the point, all levels of government have been making empty promises to people," Ryan said on the CBS program "Face the Nation." "And these governors are telling people the truth."
Walker said he hoped the Democratic state senators would return to Madison so debate on the bill could ensue, but added that all options were on the table -- including a possible contempt proceeding -- if they don't.
On Saturday, Tea Party activists supporting the bill brought a new dimension to the street demonstration. "Wisconsin is ground zero," said Tim Phillips, president of Americans for Prosperity. "I think it is going to determine largely whether the pampered nature of these public employees is finally reined in."
One of the missing Democratic state senators, Jon Erpenbach, said all state and local public employees -- including teachers -- have agreed to the financial aspects of Walker's requested concessions on paying more for employee health care and pensions.
"In return they ask only that the provisions that deny their right to collectively bargain are removed," Erpenbach said. "This will solve the budget challenge."
Walker, however, said it was necessary to change the collective bargaining rules because the alternative would be laying off thousands of state employees.
"I can't have anybody laid off," he said on FOX. "I don't want a single person laid off in the public nor in the private sector, and that's why this is a much better alternative than to losing jobs."
Until Saturday's counter-demonstrators appeared, the growing protests since Monday were largely made up of those against Walker's plan. They remained the clear majority of those marching, with many of them on Saturday drawn by the arrival of Walker's supporters.
White House press secretary Jay Carney spoke about the protests Friday, saying President Barack Obama "is very understanding of the need for state governments, governors, state legislatures to reduce spending to make tough choices to be fiscally responsible."
But he added, "He also feels very strongly that we need not to make this an assault on the collective bargaining rights of workers in any given state.
"He understands public employees need to make sacrifices just like everyone else."
Walker and other Republicans criticized Obama on Sunday for getting involved in the issue, calling it inappropriate.
CNN's Gabriella Schwarz, Tom Cohen, Casey Wian and Chris Welch contributed to this report.