Hi Khorat,
I am going through a similar situation.
I only have 3 month's left and received an email from the IP stating that. Then I had a letter saying there was an equity clause, I knew nothing about. I have to get a valuation on my house and if the outstanding balance is less than 85% of the valuation, I have 3 options.
Re mortgage the house to 85%, and give them the difference,
Pay another 12 month's,
Or make them a third party offer, which will be the 12 month's extra payments, in my case an additional £4.5k
It is unlikely I would get a re mortgage, as the lender would be wary of giving money to some one in an IVA, if they did the interest rate would be high. Also they have to be satisfied you can afford the additional payments of a re mortgage.
So, believing I was out of this after 5 hard years, was wrong !!
"It's never over till the fat lady sing's"
I will end up in another 12 month's, and like your saying, it hurts !!
If they are just asking for £1k of you, I would take it, BUT, make sure that is the F&F, with no come backs.
Good luck !!