A new GP contract started in 2004
Family doctors in England are working less, but paid more after the introduction of a new contract failed to live up to expectations, MPs said.
The Commons' Public Accounts Committee report found that the 2004 deal led to fall in productivity and working hours, while pay for GP partners rocketed.
But the MPs also pointed it out it has led to a rise in the number of GPs and a greater variety of services.
Ministers said they had already started to address the issues.
The report looked at the impact of the contract in England.
While the deal applied to all of the doctors in the UK, many of the problems have been most marked in England.
The report said over the first three years, the contract cost £1.8bn more than expected.
This was blamed on the government for underestimating the cost of providing out-of-hours care - GPs were allowed to opt out of weekend and night care under the terms of the deal - and the better than expected performance of doctors.
The contract was structured so that about a third of doctor pay was linked to performance.
But since the changes were made GPs have hit well over 90% of their targets.
Committee chairman Edward Leigh said: "It made good sense to introduce a new contract to GPs to link their pay to performance.
"Unfortunately it was far too easy for them to tick all the boxes. The result is that GPs' salaries have increased on average by an eye-watering 58% since 2003.
"Their productivity has actually declined by 2.5% and the public is poorer to the tune of £1.8bn."
The report says that GP Partners salaries now averaged £114,000 a year, although much smaller rises had taken place for salaried GPs and nurses.
This happened over a period when GPs started working fewer hours - 36.3 a week compared to 43.1 in the 1990s - and productivity fell.
The government has already responded to such trends by rewriting the GP contract this year to encourage surgeries to offer weekend or evening opening. So far nearly half have done so.
But the report did highlight some positive impacts with patients now being guaranteed appointments within 48 hours - although this had perversely resulted in some patients struggling to book appointments in advance.
The cross-party group of MPs also said GP consultations had become longer as nurses had taken on extra responsibilities including asthma and diabetes reviews.
This also meant family doctors were offering a wider range of services - in recent years they have started taking on care traditionally done in hospitals, such as minor surgery.
And the contract also seems to have brought more doctors into the profession with an extra 4,000 being employed since the contract started, bringing the workforce to over 33,000.
But Dr Laurence Buckman, chairman of the British Medical Association's GPs committee, said: "Much of the criticism in this report is based on an out-of-date understanding of the current situation.
"GP practices have taken on additional work since the original contract was agreed and practice income has been frozen."
Steve Barnett chief executive of the NHS Confederation, which represents over 95% of NHS organisations, said: ""NHS Employers has already addressed some of the areas raised in the report.
"In 2006, we made significant changes to the contract and this resulted in substantial financial savings and improved patient services. In addition, earlier this year, we provided incentives for practices to provide additional appointment times which increased access for patients."
Health minister Ben Bradshaw said moves had already started to improve services, citing the longer opening hours.
"We continue to look constantly at ways to improve the contract and the report will help inform further improvements."