Starting a second application with new lender whilst waiting for decision?

Rmphotography

Just wondering if there was a downside about putting in a new mortgage application with a new lender whilst waiting for a decision from the original lender?

Bit of background info
We applied with abbey at the beginning of MARCH for a mortgage but they have gone back and forth over my wife's income saying that as she receives her income from benefits it isn't stable. We have questionned this and sent documents showing the guy who she looks after has a lifelong condition and is never going to get any better.
It's been 9 weeks now and I am being pestered left right and centre from the Estate agent, solicitor and sellers about when we will get a final decision.
I've spoke to another lender to see if they would provide us with a mortgage and explained my wife's income and they have no issues whatsoever.

So after the long ramble my question is whether there is any harm in applying for a mortgage with lender 2 whilst lender 1 is constantly saying "another week" or "send us more information and we will send you to the back of the queue"
My naive logic says that if we are turned down by lender 1 the application for lender 2 will be more advanced and therfore less waiting. And lender 2 already knows the score with lender 1 anyway.
If we are accepted by lender 1 we could cancel the application with lender 2

suziqqq

I may be wrong but don't think you can apply for 2 mortgages at once and if you can that would involve more credit checking which will show up on your file so the bank you are currently trying to get a mortgage will see this

amnblog

One at a time.

Otherwise one application will prejudice the other.

Thrugelmir

There's no certainty that the same issues wouldn't be encountered with lender 2.