Contracts

Hi all, apologies if this has been asked before.
I have been offered a maternity leave contract until Christmas that needs to be signed by the end of the month.

I’ve covered a short mat leave already this year in a different school and I was hoping for something more secure. I know more posts go up in August so I’m wondering is it a bad idea to sign the contract now in the hope a FT comes up and break it? Or not sign at all? I’m aware doing either may jeopardise any future jobs in the school.

Any advice?

TIA