Should add - the job start is in September. There's no way I could start a new job and be off on maty leave within 2 months!

I don't hate my current job, exactly, I just don't want to do it full time any more. The new job is 20 hours a week rather than 40, and catering to a different group of people. And the place I've wanted to work for about 3 years. If it weren't for this job, I wouldn't even be looking.