TORONTO - Ontario Premier Dalton McGuinty says he welcomes protesters coming to the legislature to rally against his plan to harmonize sales taxes but hopes they'll come to understand the new tax is the right move.

McGuinty says he's always known the plan would be controversial in some quarters, because it's not an easy thing to do.

The change is needed to strengthen the province's economy, he says, especially when it comes to improving the competitiveness of the embattled manufacturing sector.

The Public Sector Retiree Coalition, which represents over 25,000 public sector retired employees, is protesting the tax increase at the legislature -- along with the leaders of both opposition parties.

NDP Leader Andrea Horwath says people in all communities have been telling her they are against the HST and they think it's an unfair tax that will hurt them at a time when they're already struggling.

The merging of the eight per cent provincial sales tax and the five per cent GST next July will increase the cost of many items currently exempt from the provincial levy.

The province has set up some measures to cushion the blow to consumers, which are supported by $4.3 billion from the federal Conservative government under a deal with the province to harmonize taxes.