The 13 per cent harmonized sales tax is set in stone, Premier Dalton McGuinty has warned Liberal MPPs in a special caucus meeting on the controversial new levy.

Amid rumblings of dissent about the tax that takes effect next July 1 — including from some Liberals who privately complain it should be cut to 12 per cent to make it more politically palatable — McGuinty yesterday said it’s full steam ahead with the 13 per cent solution to Ontario’s economic woes.

As Liberal MPPs gathered yesterday for a special caucus meeting on the HST at Bay Street’s First Canadian Place, McGuinty said he is resisting pressure to revamp the levy that melds the 8 per cent provincial sales tax with the 5 per cent federal goods and services tax.

“We have a plan in place and we’re going to stick to that plan,” he told reporters, touting the tax reform as key to cutting costs for business to help create jobs.