Quoting from Tony Merton Jones's British Independent Airlines 1946 to 1976 and taking the bits relevant to the Comet discussion:
In April 1969, a five million pound contract was awarded by Lyons Tours to operate their inclusive tour flights from 1970 until the end of 1972. With the award of this large contract, Channel was required to buy further jet aircraft but the lack of finance caused the selection to be a fleet of former B.E.A. and Olympic Airways Comet 4Bs. The contract for the purchase of these aircraft was signed on August 27 1969, and the price paid was a figure a little under two million pounds.
Throughout 1969, in addition to its inclusive tour flights from Southend and Stansted, Channel Airways also flew jet inclusive tours from Edinburgh and Teesside to Alicante, Gerona, Ibiza, Palma and Venice. The first of the Comets to be delivered (G-APYC) arrived at Stansted on January 26 1970, and fitted out with 109 seats, these aircraft flew services from Birmingham, Bristol, Glasgow, Manchester, Newcastle and Stansted to Alicante, Basle, Gerona, Milan, Palma, Rimini, Tangier and Trieste. In addition, further jet inclusive tour charters were flown from Bournemouth, East Midlands and Teesside on behalf of other tour operators including Mediterranean Holidays and Trident Holidays (both subsidiary companies of Channel Airways). A weekly Viscount service was also flown from Birmingham to Ostend and from Manchester, the 1-11s flew inclusive tour charter flights to Basle, Gerona, Ibiza, Malaga, Milan, Palma, Rimini, Valencia and Venice.
One of the Comets (G-APYC) flew Channel's first Comet inclusive tour service from East Midlands Airport on May 17 1970, when it carried a party of holidaymakers from Castle Donington to Palma. This service was flown weekly throughout the summer, and most of Channel's Comet services for Lyons Tours also started in May 1970.
In September 1970, the airline announced another large inclusive tour charter contract, worth £11 million, which required the airline to operate flights from West Berlin to Southern Europe and North Africa. These flights were operated on behalf of three West German tour operators G.U.T., Neckerman and Stolle, and over fifty flights a week were operated to Greece, Italy, Romania, Tunisia and Yugoslavia. These services started in March 1971 and during the summer, they almost fully utilised one Trident and one BAC 1-11.
The book was a re-publication in 2000 by The Aviation Hobby Shop of the original four-volume series published in 1976 (pleased to have both) and a go-to volume for anyone with an interest in this type of thing!