Image copyright Northern Image caption A total of 101 new trains will enter service with the company

Northern has officially launched its new trains, promising the biggest services upgrade "for a generation".

The firm, which is owned by Arriva Rail North, said the first nine trains of a new £500m fleet will start carrying their customers from 1 July.

The rest of the company's 101-strong fleet will be rolled out every month over the next year.

In the past year, Northern has been affected by widespread rail timetable chaos affecting services country-wide.

The trains, Class 195 and Class 331, will mark a step-change for rail travel in the north of England, Northern said.

Customers have been promised plug sockets at every seat, free Wi-Fi and live-feed information screens.

The new trains, which include more space for wheelchairs and cycles, are described as "bigger, faster and longer" than the company's existing trains.

Image caption The new trains are replacing the Pacer trains

The first nine trains will operate on routes between Cumbria and Manchester Airport, Liverpool and Manchester Airport, and between Doncaster and Leeds.

Richard Allan, deputy managing director of Northern said: "These new trains represent a huge improvement in design, quality and overall experience for our customers."

Rail Minister Andrew Jones said: "We are one step closer to saying goodbye to outdated trains and the start of a more modern rail network fit for people across the north."

Northern is also refurbishing its existing fleet of 243 trains.

It said it was committed to retiring the much derided Pacers - which were essentially a bus frame on train wheels - by the end of 2020.

A lot of the Pacer fleet will be replaced by refurbished trains.

Last month, the elected mayors of Greater Manchester and Liverpool City Region urged the Government to take control of Northern arguing it had failed to deliver promised improvements.

The company has been accused of cramming commuters on to smaller trains and with passengers facing regular delays.