WARSAW, Jan 15 (Reuters) - Polish interest rates could drop below zero if the coronavirus pandemic causes further, significant damage to the economy, central bank governor Adam Glapinski said on Friday, adding that his base scenario was no change in borrowing costs.

A move to negative borrowing costs would be uncharted territory for emerging Europe's largest economy, where the benchmark rate has been at a record low of 0.1% since May, but Glapinski said the situation would have to get much worse to justify it.

"Yes, I allow for rate cuts. Yes, I allow for negative rates," Glapinski said in comments broadcast on the bank's web page.

"This would have to be connected with a radical deterioration of the economic situation, and we assume, on the contrary, that this year the economic situation will gradually improve."

He said the base case scenario was stable rates until 2022.

Glapinski also said the bank had intervened on the foreign exchange market since mid-December to prevent a sudden rise in the zloty currency.

While declining to say exactly how big the interventions had been, Glapinski said their size had been "significant" and "incomparable to any other previous intervention".

However, Glapinski said that the bank did not have a specific target for the value of the zloty and that, while the central bank could intervene in the market, it would continue to have a free-floating exchange rate.

"We do not strive to maintain the rate at a predetermined level," he said. (Reporting by Alan Charlish, Pawel Florkiewicz, Justyna Pawlak and Anna Koper; Editing by Toby Chopra)