The investment in eight KBA Courier presses and Idab Wamac mailroom kit will allow the south-east London plant to print The Daily Mail at 128pp with 64pp of colour.

The Mail on Sunday can be produced at 168pp with 128pp of colour on the eight-unit presses, which also feature the world's largest colour register system from QI Press Controls.

The presses are capable of producing up to 80,000cph of Associated Newspapers titles, which also include The Evening Standard and Metro. Harmsworth Quays prints 2m newspapers every day.

DMGT chairman Lord Rothermere said that the investment would allow the plant to produce "more colour, more pages and better-printed newspapers than anyone else in the country".

He added: "I would like to congratulate our management team who have done a brilliant job coming in below budget and almost 12 months ahead of schedule.

"While our rivals are still talking about their plans to replace old equipment, we have quietly done it."

As well as the investment in Harmsworth Quays, DMGT has upgraded plants for its Northcliffe Newspapers regional newspaper group in Stoke, Derby and Bristol.

The completion of the plant marks the end of a major shake-up of printing arrangements for Associated Newspapers.

During the summer, the press group revealed plans to shift the bulk of its 60m supplement printing contract from Quebecor World to Polestar's new gravure site in Sheffield.

Story by Josh Brooks