Outstanding invoices

Hi, I've just found this site as I'm starting to get worried about three outstanding invoices that are owed to me from the same company. The company in question is a large commercial property company. I am set up as a limited company.

I provide security services for a commercial client in the UK. I'm contracted to a commercial landlord but never deal with them directly as all correspondence, invoicing and payments are made/sent through a management company.

I have worked with the same client for the past three years. They've always been slow in paying their invoices but have always done so up until the start of 2016. I always invoice at the start of the following month and have a 21day payment term in the contract bit to date I am owed for security services for January to March which totals around £32k. April is due on the 21st May but I have little hope of this being paid on time.

I've chased the management company directly using phone calls and emails but they are stating that there are no funds in this clients account so can't make payment to me. I know that the site that I secure is currently up for sale and suspect that the landlord is delaying payment in the hope that the debt can be sold with the buildings.

I've covered all wages up until this month but I can no longer afford to do so any longer. It has now got to the stage where I will have to remove my staff from the site to avoid an additional wage bill at the end of the month.

I have explained this to the management company who are in contact with the landlord but there seems to be very little progress.

I would be grateful for any advice anybody could give on how to proceed with this.