Might not be impossible ..best to get some professional advice. The forum has two mortgage experts Ryan and Shaun - their contacts are in the link below.
Everyones circumstances are different and although likely you will need to wait it is not too early to speak to them. I can personally vouch for Ryan
You will probably have to wait until 6 yrs after the start date of your Iva as a minimum. Ive just remortgaged with first direct without using a broker and its gone through fine. My 6yr Iva ended this year and first direct said as long as I haven't entered into an Iva in last 6 years then its not a problem