Your claim for unpaid wages and benefits will be administered by the Department of Work and Pensions under the National Insurance Fund. Your employer's IP should have provided you with Form RP1 to enable you to submit your claim against the employer, and the DWP will then pay you (subject to some monetary limits) and then become the creditor instead.
So sorry to contradict jpj, but you will get your claim paid and relatively easily. Your employer and the IP should be providing you with more assistance with this, and if they do not send you the form over the next couple of days e-mail me at the office and I will send you one with an explanatory booklet detailing how to submit the claim.
I have attached a link which you might find helpful, and I think that the form is also downloadable from this site.
http://www.insolvency.gov.uk/guidancele ... forips.htm
Let us know how you get on.