Having just read this post following my return from holiday, I find this matter rather odd! It is possible that adequate representation has not been made to this creditor, as I assume that your partner was going to continue to discharge the debt under normal contractual requirements as she is jointly liable, from her own disposable income, leaving you with your own income to make your IVA contributions.
In these circumstances, there is no real problem in leaving the debt outside of the IVA, so long as all creditors are aware of what is happening and agree to such treatment - but they of course do have the ability to vote in the proceedings. You would have to convince the creditor concerned that your partner is able to make the ongoing payments comfortably in her own right.
At the end of the day, the creditor wants their debt repaying, and your partner is jointly liable in any case - so what is the problem?
This creditor takes a lot of stick on this forum, and yes they do have a different view to voluntary arrangements from other creditors, but at the end of the day I personally still find them very commercial and able to discuss issues directly.
You may wish to consider seeking an opinion from an alternative insolvency practitioner with a view to representing this proposal, which may also be in the best interests of the 60% of creditors who supported your proposals.
Regards, Melanie Giles, Insolvency Practitioner for over 20 years.
For further details contact me at
http://www.melaniegiles.com and view my IVA blog at:
http://melaniegiles.blogs.iva.co.uk