Workers spend on average 75 minutes a day travelling to and from work in London, compared nationally with 52.8 minutes, the TUC said.
Wales sees the fastest commutes, an average of 41.4 minutes travelling, down 4.6 minutes since 2006.
The study compares pre-recession travel times of 2006 with those of 2012 and found the average commute was the equivalent of five weeks a year.
The TUC analysed the figures from the Labour Force Survey to mark Commute Smart week.
The study found that men working in the east of England saw the sharpest rise in travel times - up 3.8 minutes to 65.2 minutes.
But in London even though men spend just above 77 minutes commuting, the figure has fallen by 1.8 minutes since 2006. The study attributed the drop to an increase in part-time work, especially among men.
The trend was bucked by the capital's women workers who saw their travel times rise by three minutes to 72.8 minutes.
The TUC's General Secretary Brendan Barber said: "With rising transport costs far outstripping pay rises, reducing the number of peak-time commutes would save both time and money for hard-pressed workers.
"Recent trends suggest there is a link between long commute times and longer hours in the office, with the growing number of men in part-time work having shorter journeys to work.
"This trend is concerning if it means part-time workers and those needing to balance work with caring responsibilities are being excluded from certain types of jobs."
Phil Flaxton, chief executive of Work Wise UK, urged employers to "revise tired working practices" and adopt "flexible approaches to people management".

The Spaniard won the European Cup both as a player and a coach (twice) with the La Liga side.
He goes back to the Nou Camp in the Champions League next week knowing the task facing his City side is immense.
"Barcelona are special in the way they play. They're a machine," he said.
With former Barcelona officials Ferran Soriano and Txiki Begiristain as chief executive and director of football respectively, and Guardiola as manager, there is clear influence from the Catalan giants at City.
But Guardiola knows it is going to take time to achieve the identity Barcelona have forged over the past half a century.
"For the last decade, the last 50 years, Barcelona dominate football matches. I love the way they play," he added.
"They have three amazing players - Lionel Messi, Luis Suarez and Neymar - up front. They are amazing on the counter-attack. They have a good build-up. They are a good team."
Guardiola accepts City may have a confidence problem facing Barca, given Saturday's 1-1 draw against Everton in the Premier League means they have gone three games without a win.
Kevin de Bruyne and Sergio Aguero both had penalties saved by Everton goalkeeper Maarten Stekelenburg, meaning Aguero has failed five times from the spot so far this season, including two for Argentina.
Guardiola says he does not have a problem with that, and Everton manager Ronald Koeman, who played with him in Barcelona's European Cup final success over Sampdoria at Wembley in 1992, feels City have nothing to worry about at all.
He said: "They are the best team I have played against in my managerial career.
"If you look to the football, to the offensive style, the movement, the quality of the players in midfield and in front, then they are the best team in the Premier League.
"Maybe we didn't deserve a point on chances but football is unpredictable and our goalkeeper maybe played his best game ever."
Londoners face the longest average daily commute in the UK, a study found.
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Barcelona are a "machine" who are likely to dominate possession against Manchester City on Wednesday, says the Premier League club's manager Pep Guardiola.