The best option is to repay the ovedraft.

1.5% per month equates to an apr of 19.6% which could be worse (it could be better too). Banks can change the interest rate on overdrafts at any time and they can also demand repayment of the overdraft at any time. Overdrafts are not suitable for long term borrowing.

If you had a credit card with a £3k facility with "0%" interest on balance transfers, you might be charged about 3% for the cash advance plus another 3% or so for the transfer. Many "0%" deals only cover transfers between two credit cards so you may need to get a cash advance on one card and then transfer that to another card to make use of the deal. Some cards do issue credit card cheques at a reasonable interest rate.

Realistically you need to put a plan in place to pay off the debt with your own money over the next months. Juggling with credit cards and so on may provide a little short term relief but it wont make the debt go away.