Liberal Democrat peer Shaffaq Mohammed, who lives in Sheffield, said he had recently been impacted by rail disruption while travelling to the House of Lords.
“We have either had cancellations or delays for weeks now,” Lord Mohammed said.
“Recently my train set off from Sheffield on time, but the journey was delayed and they said due to ongoing faults it was terminating at Leicester.
“The train was already quite full because EMR have cut a number of services.
“We waited half an hour and then had to join another train which was already full.”
He continued: “On another occasion, my colleague Paul Scriven was on a train an hour before me. His train then developed a fault and had to pull over.
“He waited on a platform for 25 minutes to join my train, but it was already jam-packed so we both stood up the whole way.”
Lord Mohammed says he had raised the issue with rail minister Lord Peter Hendy.
The Department for Transport said it had asked EMR “to do everything possible” to minimise disruption and make services more reliable.
The delays are due to problems transitioning to a new fleet of trains.
Manufacturer Hitachi Rail said the new fleet had been in passenger service with EMR since December 2025 and more than a third of the fleet had now been delivered.
It said it was working closely with industry partners, implementing improvements and was focused on delivering the remainder of the fleet and supporting EMR as more new trains enter passenger service.