Monarch had a declared seat capacity of just over 750,000 seats this winter according to ACL.
Now, we know not all of those seats will have been filled, but if we work on an average load factor of 85% (a realistic figure), then that's a loss of 637,500 passengers. Monarch had less of a seasonal variation than some other carriers at MAN, so x2 that's a loss of 1.2million pax.
Jet2 have added 300,000 seats next summer, TUI about 100,000 and Thomas Cook will probably be around 100,000 pax themselves. Easyjet will have at least one extra aircraft next summer, possibly 3 so we can say that's between 100,000-250,000 of extra pax.
Then add in all the other increases such as Cathay going daily, Oman Air still adding into the pax figure until May, Virgin adding 40,000 seats, Air Arabia Maroc, Powedair and such, that's potentially another 100,000. So, we are looking at 800,000 seats.
However, we also have the Loss of Norwegian sun routes, vueling ALC/TFS/FCO and no doubt other little losses over time, then that's probably about 100,000 lost.
Therefore, I fear MAN may start entering the negative territory, unless something is pulled out of the bag, to which I'm hearing rumours there may be something in the offing, but, no concrete rumours.