OTTAWA - Finance Minister Bill Morneau says 50 Canadian companies have so far been exempted from paying surtaxes on U.S. steel and aluminum imports that have been in place since Ottawa imposed retaliatory tariffs last summer.

Morneau provided the figure Tuesday before a parliamentary committee, where opposition MPs criticized his relief plan as too slow in helping Canadian firms affected by the cross-border tariff fight and too onerous for smaller companies to even apply for.

Conservative MP Dean Allison says the committee has heard from many businesses caught in the crossfire that are worried the financial relief isn't arriving quickly enough for them to remain viable.

Under questioning, Morneau agreed he would like to see the relief money flow faster - but he said there's a process that must be followed.

He says 135 companies have submitted remission requests and approved firms will also be eligible for refunds on duties they've already paid since Ottawa imposed the counter-tariffs on U.S. products on July 1.

Morneau was asked how much extra revenue the surtaxes have already brought in - but he declined to provide a number and only said the duties were generating significant revenues.