Why not?No!!!
While it's unlikely that any lender would charge, say, 15% right now, I'm not aware of anything to stop them (other than fixed rate and tracker loan agreements).
Mortgage Interest Rates
Mortgage Interest Rates Dáil Éireann Debate, Tuesday - 22 February 2022
www.oireachtas.ie
The price lenders charge for their loans is a commercial matter for individual lenders. As Minister for Finance I cannot determine the lending policies of individual banks including the interest rates they charge for loans including mortgages.