London mayoral candidates clash over transport
Transport topped the agenda when the four main candidates to be London mayor clashed at a hustings in the City.
Conservative Boris Johnson attacked Ken Livingstone for his promised Tube fare cut, but the Labour candidate accused him of "sitting on money" rather than helping hard-pressed commuters.
Lib Dem Brian Paddick urged "smarter" use of Heathrow to increase capacity, while the Greens' Jenny Jones suggested a congestion charge around the airport.
The election will take place on 3 May.
The hustings, hosted by law firm Allen and Overy, were designed to focus on issues relating to business in the capital.
It was the first time the four main candidates for mayor have shared a platform ahead of this year's vote.
Mr Livingstone, who was mayor from 2000 to 2008, defended his plan to cut London Underground fares by 7% and bus fares by 11%, insisting "that's what can be afforded without impacting on investment".
He said there was a surplus of money underspent by current mayor Mr Johnson, adding: "I say it is completely unacceptable for any layer of government to be sitting on money they are not using."
The Labour candidate pledged to create new deep tunnels under London to increase suburban transport links, including one between Euston and Waterloo which could carry 25 trains in each direction an hour.
Mr Johnson, in office since 2008, hit back repeatedly though at the planned fare cut, calling it "cretinous" to consider reducing money for the Tube at a time when demand is rising.
He accused Mr Livingstone of presiding over "delusional projects" while in office, such as the west London tram proposal which was eventually scrapped.
When the candidates were asked about the power of the Tube unions, all four were highly critical of the tactics used by bosses such as the Rail, Maritime and Transport's Bob Crow.
Ms Jones accused Mr Crow of "screwing money out of the system", while Mr Paddick said it was time London "had a mayor to stand up to the unions," but added: "We have to be prepared to suffer as commuters as a consequence."
Mr Johnson went even further, telling the audience: "I'm absolutely ready over the next four years to take historic decisions that will modernise and automate our trains and enable them to be driverless."
The subject of Heathrow was also a key topic, at a time when the government is consulting on aviation policy, but has ruled out a third runway at the airport.
Mr Paddick proposed cutting the number of short haul flights from Heathrow, replacing them with more to emerging long haul destinations.
"We can do that now rather than waiting 20 years for a fantasy airport to come on stream - or should that be in stream," he said.
That was a reference to Mr Johnson's proposal for a new airport in the Thames Estuary - something the mayor resisted mentioning at Thursday evening's event.
Ms Jones said the idea of increasing aviation in the UK "in any way is barking mad", adding: "It's not only dinosaur thinking, it's dangerously irresponsible."
She said alternatives to cut the amount of travelling people need to do for business, for example by video-conferencing, should be a priority instead.
Away from transport, the candidates were asked about their views on a possible mansion tax for rich homeowners, and about the government's cap on migrants from outside the EU, which business leaders have said is hampering their ability to recruit talent.
The four were in broad agreement about both issues.
Mr Johnson called the mansion tax "unjust" while Mr Paddick branded it "fundamentally unfair" and acknowledged he was "going off message" by disagreeing with senior Lib Dems like Vince Cable who support it.
Ms Jones said she believed there should be free movement for labour, while Mr Livingstone focused on efforts that could be made to increase the number of Chinese tourists able to come to the UK.
He suggested allowing anyone from China with a visa to Schengen countries - those in Europe who have open borders - to come to the UK on the same visa at no extra charge - something Mr Johnson backed.
On encouraging enterprise, Mr Paddick called for the creation of an office for small business within City Hall, while Ms Jones suggested moving London's budget to banks that could prove their commitment to helping small firms.
The Conservative, Labour and Lib Dem candidates all agreed that parking was a major problem for local high streets around the city, with Mr Paddick summing up their view by saying borough councils were "persecuting motorists" via parking tickets as a way of raising revenue without increasing council tax.
The London Mayor and Assembly elections will be held on 3 May 2012. In order to vote you must be registered before 18 April.