Thanks both for the replies, I really appreciate it. We have both been so stressed about it over the weekend that we have hardly slept.
We have the approval in principle at the moment and were going to look for the full offer letter this week.
When I mentioned the potential new job to our broker, we were advised not to change as we haven't a hope of being able to draw down if my wife is on probation. And if we apply again would have to wait till after probation (and of course in that time we would lose the house)
Apparently, the banks are now looking for your most recent pay slip just before drawing down the money, so would see if she is in a different job. Hence thinking we would not take the new job, which is gutting!
Having said that, after seeing your replies, we are going to push the broker to see if it is possible. Fingers crossed!
Thanks again!