Deputy Labour leader Harriet Harman has played down comments by Ed Balls comparing the HS2 project to the Millenium Dome.
Speaking on the BBC's Andrew Marr Show, Ms Harman said Mr Balls did not volunteer the comparison during an interview with a Mail on Sunday journalist.
The shadow chancellor told the newspaper the Dome was a mistake, adding "I think you should learn from your mistakes".
Ms Harman said: "We absolutely support better north-south lines, we are in favour of rail infrastructure for commuters and also for long-distance travellers and freight but not at any cost and what Ed Balls is saying is we have to keep a strong eye on the costs as well as on the benefits."
Labour deputy leader Harriet Harman has said she is against lads' magazines in supermarkets - but is not in favour of a ban.
Speaking as one of the guests on The Agenda with Tom Bradby to be broadcast on ITV at 10.35pm tonight, Ms Harman said: "It's possible for there to be a view and to have a campaign without being accused of banning something.
"I think that women in the 21st century can aspire to more than being sex objects for the titivation of men.
"Would you like your daughter to be on the front page of Zoo or Nuts or Loaded?
"It is a very powerful image that a woman's value increases with the lack of clothing that she's wearing. Don't accuse me of trying to ban it, I'm just against it."
Labour MPs will today put pressure on the government to introduce tougher measures to protect children from violent online pornography.
Search engines must introduce safe searches to ensure children are not exposed to explicit content, as well as effective barriers to prevent under-18s accessing pornography online.
The MPs, led by leader Ed Miliband and deputy leader Harriet Harman, will vote for an Opposition Day motion in the Commons calling on the Government to set a timetable to introduce tougher rules for internet companies.
In the wake of the Mark Bridger and Stuart Hazell cases David Cameron has demanded Google do more to rid the internet of child pornography, warning that lives are being put at risk.
Web search firms have been summoned to a council of war with Culture Secretary Maria Miller and the Prime Minister's adviser on the issue, Tory MP Claire Perry, next week.