Buying girlfriend(ex) out of property

Hi I'm looking for some advice.

My brother broke up with his girlfriend and they share a mortgage and flat in Dublin. They hope to sell the flat for 300k-310k. There is a 232k (plus 25k owed to my mum) mortgage on it. He knows that if he sells it and split the difference and after the vultures take their cut there wont be much left. He wont be even able to pay the tax on a new place.

What I'm asking is it possible to convert over to a buy to let mortgage at the same time as buying her out because he wont be able to keep up the repayments on his own. The flat is in Pearse St, so it should get a decent rent, maybe 1k a month- its a 1bed.

My mum should be able to hold on for a while and I think he gets about 1.6k after tax. thanks

His after tax income would indicate a gross annual salary of approx €22,000 per annum, his income is not going to support the mortage as it stands at €232,000 never mind a higher amount to repay ex partner.
Even as an investment.. if tenants dont pay rent , he still has to pay a mortgage... he is looking for in excess of 10 times his salary, cant see it being a runner to be honest.

Thanks for the speedy reply.

Just thinking out loud now but If I were to help him get the mortgage with my salary, 2240 after tax would I have to pay stamp duty, I'm already a home owner. The reason being, he's on the ladder now, I dont want him to get off it.