Section 20 Major Works: undisclosed connection between landlord and winning bidder

[AB2017]

Hi, our landlord is running a section 20 consultation for a major works contract. He obtained three quotes, one very high, the second very slightly cheaper and the third very low. The third was disqualified, purportedly on the grounds that they must have misunderstood the job. The second bidder has therefore won the job, and we have now discovered that this contractor is in fact owned by our landlord! We suspect he waited for the first bid to come in (possibly even asking the contractor to bid on the high side) and then submitted a slightly cheaper one in order to win. I know the landlord is obliged to disclose any connection with a contractor for Qualifying Long Term Agreement consultations, but strangely there doesn't seem to be a similar obligation for Major Works consultations - the only thing I can see is the obligation to obtain at least one quote from a non-connected bidder. Is there anything we can do to challenge this selection?