He doesn't agree with Quebec's controversial secularism bill but Liberal Leader Justin Trudeau says he will sit this one out -- for now.

Trudeau is spending today and much of tomorrow travelling through the seat-rich province of Quebec, focusing on ridings previously held by the NDP that the Liberals think they can turn red.

But while trying to woo voters in Trois-Rivieres, Longueuil and Montreal, Trudeau is also carefully trying to avoid getting pulled into delicate provincial matters that could whittle away at his political ambitions in Quebec.

He told reporters today he opposes Bill 21, which bans some public servants from wearing conspicuous symbols of religion, but he will not get involved in a legal challenge that has been launched against the legislation.

"I think Quebec voters know full well that I will always defend individual rights and freedoms and indeed that I disagree with Bill 21. I don't think, in a free society, we should be limiting fundamental rights or allowing discrimination to happen," he said during a media event in Trois-Rivieres this morning.

"We are weighing whether to intervene. At this point we do not think it would be productive."

Bill 21, which came into effect in June, prohibits public servants in positions of authority such as judges, police officers and teachers, from wearing any religious symbols, including turbans, kippahs and hijabs.

The Coalition Avenir Quebec (CAQ) government invoked the notwithstanding clause of the Constitution when passing the bill to block any possible Charter challenges, but a legal case has nonetheless been mounted by the National Council of Canadian Muslims and the Canadian Civil Liberties Association to strike down the law.

Quebec Premier Francois Legault issued a stern warning to all federal political party leaders to keep the law off the federal agenda during the election campaign -- urging them to promise not to challenge it in court, noting strong support among Quebecers for the secularism law.

Earlier this week, Trudeau said he believes it would be counterproductive for the federal government to get involved in this court challenge.

"I'm not going to close the door on intervening at a later date because I think it would be irresponsible for a federal government to close the door to intervention ever on a matter that does touch fundamental freedoms."

But for now, he says, the process is unfolding the way it should: as a provincial matter.

"This is a discussion happening among Quebecers right now and their provincial government," he said.

"The Charter of Rights and Freedoms exists so that citizens can challenge laws that they disagree with, that they feel are an unnecessary limitation on their fundamental rights and freedoms. That's why we have a charter and it's being used right now and it's being used by citizens in Quebec to contest, before the courts, this law that they feel is unfair and limiting their own rights and freedoms."

Meanwhile, the Liberal leader hopes his platform pledges and his time and attention to Quebecers in the province today and tomorrow will convince progressive voters to abandon the NDP and instead vote Liberal.

In the morning, he unveiled a package of pledges that he said will boost small and medium-sized businesses.

For one, Trudeau announced that a re-elected Liberal government would eliminate the so-called "swipe fee" on sales taxes that merchants must pay to credit-card companies on every transaction.

Business groups have been calling on governments to ban the charge and, according to an estimate by the Canadian Federation of Independent Business, the move could save merchants nearly $500 million per year.

"Our owners of small and medium-sized businesses continue to be a powerful motor of growth for our communities," Trudeau said in French in Trois-Rivieres.

He credited smaller businesses with helping drive Canada's strong run of job creation in recent years.

If re-elected next month, Trudeau said, the Liberals will also reduce the cost of federal incorporation, remove all fees for business advisory services from agencies like the Business Development Bank of Canada, and create a voluntary payroll system to automate records for small businesses.

A Liberal government would also launch a pilot project that would provide as much as $50,000 for up to 2,000 entrepreneurs to help them start businesses and give $250 to every new business to help them develop websites or e-commerce platforms.

The Liberals estimate the combined measures would cost the federal treasury $129 million next year, a number that would rise to $163 million in 2023-24.

Dan Kelly, CEO of the Canadian Federation of Independent Business, says he welcomes the pledges -- especially the promise to eliminate the credit-card fees on sales taxes.

"The Liberals are the first out with promises to small business and it's a fairly significant one," Kelly said in an interview.

"Credit-card processing fees, for the last decade, have been a huge tailwind for small and medium-sized firms in Canada."

He added that, overall, smaller merchants used to pay among the highest credit-card fees in the world. The fees have started to come down a little bit in recent years.

In 2014, when the Harper Conservatives were in office, Visa and MasterCard voluntarily agreed to reduce their average effective fees to 1.5 per cent over five years, beginning in April 2015.

The Liberals announced last year that starting in 2020 the credit-card companies will trim their fees again to an average annual effective rate of 1.4 per cent.