It appears the CAA have charted 2xUnited 744s, an Omni 767 and an Air Transat A330 to operate a series of flights over the next 7 todays to/from the UK to typical bucket and spade destinations.
All the flights are flying into the UK full, but ferrying back out empty then returning full again.
This type of operation is only ever seen after the collapse of a major tour operator/airline.
A lot of the United Airlines 744 schedules tie in directly with Monarch scheduled flights.
Make of this what you will
And your source is? Put up or shut up.