The Transport Select Committee called on the Government to try and amend European Union regulations so carers fly free of charge if an airline requires them to be present because the person they look after cannot perform an emergency procedure alone.
Describing access to transport for disabled people as "unacceptably poor", the committee said the Department for Transport (DfT) was watering down or abandoning key accessibility improvements and losing the momentum that followed last year's Paralympic Games in London.
Reforms to train all bus drivers in disability awareness, require train operators to bring in "organised assistance" for disabled people as standard, and introduce financial incentives to ensure all taxis and private hire vehicles are fully accessible within ten years were also among the committee's recommendations.
Improving access to transport would help reduce the benefits bill as more people would be able to go out and work, the MPs said.
Improving accessibility would make it easier for disabled people to take up education and training opportunities, as well as visit cafes, bars and shops, thereby boosting consumer spending.
Launching the Access To Transport For Disabled People report, committee chair Louise Ellman said: "Changes made ahead of the 2012 Paralympic Games delivered access for disabled people to significantly more parts of the public transport network for the first time and highlighted the immense value of such improvements for all. Yet a year later, there is a risk that some of the momentum from London 2012 is being lost because further key accessibility improvements planned by the Department for Transport are been watered-down or abandoned."
Alongside the committee's call for bus drivers to be given awareness training, the MPs said there should be a national publicity campaign to make sure passengers better respect space intended for wheelchair users.
Ms Ellman also insisted bus operators who claim to offer accessible routes but then fail to do so should be penalised as the lack of reliability means many disabled people do not even consider making a journey by bus.
The committee said there was still a need for railway stations to be properly staffed even as accessibility improvements are made.
Ms Ellman said: "Making physical improvements to stations also doesn't take away from the importance of having staffed stations to help all travellers make safe and secure journeys."
The MPs called for the Cabinet Office to set up a working group of ministers and officials to improve cross-government working on accessibility to ensure the benefits of improving accessibility were felt throughout society.
Guy Parckar, head of policy and campaigns at the charity Leonard Cheshire Disability, said: "Today's report highlights that action is still needed to make transport accessible for disabled people.
"As the report states all too often, disabled people find that inaccessible transport prevents them from enjoying the same opportunities as anyone else. It can mean people turning down jobs, missing medical appointments, ending up trapped and unable to get out and about.
"In our evidence to the committee, Leonard Cheshire Disability set out some proposals to improve access to transport for disabled people. We have seen some change for the better, but we should be looking to make the UK the world leader in access for disabled people. A transport system that really is accessible for everyone must be at the heart of that."
A DfT spokesman said: "This Government knows how important high quality, accessible public transport is for people with disabilities and we are taking action.
"For example, our £370 million Access for All programme is delivering improvements at over 1,000 train stations and we recently announced an additional £100 million to carry the work of the scheme forward.
"We thank the committee for its work and will respond to the report and its recommendations in due course."