It is highly unlikely that you will be able to remortgage.
Usually what happens is that you will be expected to pay an extra 12 months in lieu of equity.
I would speak to your IP about this.
Sharing from experiences of dealing with debt
The greatness of a man is not in how much wealth he acquires, but in his integrity and his ability to affect those around him positively.
Bob Marley. http://kallis3.blogs.iva.co.uk
Your terms may be different but my Chairman's Report states that I have to attempt to raise up to 85% of my half of the equity as the mortgage is joint and my wife's equity is not affected. e.g. If you have £40,000 equity in your property and it is a joint mortgage then you have to try to raise up to £17,000. £40,000 divide by 2 is £20,000 and 85% of £20,000 is £17,000.
But as Kallis says, the chances of getting a remortgage are virtually zero, so you will probably be looking at an extra 12 months payments instead, but check your Chairman’s Report or with your IP for precise clarification.