A House of Commons motion criticises rail firm Connex for changing the way passengers complain about standards of service.

David Lepper, MP for Brighton Pavilion, said the change was deterring commuters from complaining.

He plans to support the motion, laid before the House by John Austin, MP for Erith and Thamesmead in London.

Connex is expecting to hear next month if it has won its bid to continue running train services from Sussex to London in the face of competition from Govia, which owns Thameslink.

The Shadow Strategic Rail Authority will base its decision on factors including customer satisfaction.

The motion criticises Connex for scrapping an e-mail address which customers could use to make complaints. Instead they have to visit the firm's website and fill in ticket details before the complaint can be registered.

The motion says: "This may be useful to Connex marketing, but it is not relevant to its customer's complaint. We fear that such a complicated procedure will inevitably deter legitimate complaints and reduce the volume of such complaints and thereby reduce the complaints statistics in the run-up to the renewal of the Connex franchise.

"We urge Connex, and any other train operating company which follows the same practice, to reinstate its direct e-mail service so that its customers may readily make their views known via all types of communications media, including e-mail, which is increasingly a preferred route for those with access at home or work to electronic mail."

Shelley Atlas, of Brighton Line Commuters, said: "I totally agree with the motion, people should not have to spend more time making complaints. This new procedure will put people off who don't have time to go through the process."

Connex spokesman David Ewart said the firm received about 2,000 complaints a month from customers.

He added: "We believe in standardising the system and have made it easier for customers. Customers are increasingly using the facility on our website to register complaints.

"We also make pre-paid reply forms available to our customers and all their letters and phone calls are dealt with at our customer call centre."

He said customer comments were valuable.