Unusual redundancy situation - HELP!

joyrider99

I have been employed by a high tech startup in the UK for the past four years. Over that time the company has expanded and contracted in personnel depending upon the finances/investment to just a few of us now.
We heard the company was in financial difficulty over the past few months and has been struggling to get new investment.
The CEO (who is also the main investor) met with us a couple of months ago and said that liquidation of the UK company was on the cards but he would strive to keep paying us as long as possible until he could sell or offload the company with a merger. He also planned to keep the US (parent) company running which is essentially just a shell company but owns the IP of the UK company.
We have been paid the last couple of months but directly from the CEO for our net salaries. Today we received notification from an insolvency practitioner that the company was going into creditors voluntary liquidation and we should fill in a form RP1.
To complicate matters we have been in negotiation with another small high tech company regarding a potential merger. This company has agreed to merge our operations and pay the ongoing operating costs of our business for a trial period of three months but not the salaries of our remaining staff. These will have to be paid by our CEO during this period.
We all have quite a few concerns with this situation given that we are basically redundant now and are expected to work as contractors with no employment contracts (some of us were on three months notice before) until a possible merger occurs. There is also no guarantee we will continue to get paid, other than the CEO's assurance that he will do what he can for the next three months.
A couple of us also have redundancy insurance but are quite worried about how this could be invoked at any point especially if we are paid in the meantime from the CEO. We are also unsure how to fill in the RP1 with regards to salaries owed etc.
Anyone have any advice..?!