Ontario Premier Dalton McGuinty is rejecting key recommendations from the province's own task force on competitiveness, including a call to harmonize provincial sales tax and the GST.

The report, released Tuesday, also urges Ontario to cut corporate income taxes.

It recommends Ontario consider a revenue-neutral carbon tax in order to meet provincial and federal targets to reduce greenhouse gas emissions.

But McGuinty says reducing corporate taxes would only create more financial trouble for the province. And he says harmonizing the goods and services tax and the provincial sales tax would drive up the prices of many consumer goods.

McGuinty says he would only consider harmonizing the sales taxes if Ottawa offered financial help, which is unlikely.

Ontario is currently facing a $500-million deficit this year, which McGuinty has warned could balloon if the province moves to bail out struggling automakers.