A railway line through the "brain-belt of Britain" will be built to serve new garden cities, Nick Clegg has announced.
Stations along the express route from Oxford to Cambridge will be granted to up to five towns that agree to build between 9,000 and 15,000 homes, the Deputy Prime Minister said.
Britain faces a housing crisis. Garden cities are a vital cornerstone of our plan to boost house building to 300,000 homes a year - enough to meet demand and keep prices in reach - while still protecting our precious green space and preventing urban sprawl. Our plan is to build a series of high quality new towns and cities where people want to live, with green space, sustainable transport and spacious homes.
The Conservatives have held back the development of garden cities on the scale necessary, but if Liberal Democrats are part of the next government, we will ensure at least 10 get under way - with up to five along this new Garden Cities Railway, bringing new homes and jobs to the brain-belt of South East England.
Nick Clegg has said the Conservatives and Labour are presenting the British public with a "dismal choice" at the next general election.
"Those choices, either sticking your head in the sand or beating up on the poor are not the choices the British people want," the Deputy Prime Minister told BBC's The Andrew Marr Show.
"They want balance between a stronger economy and a fairer society and that is what we're offering," the Lib Dem leader said.
Nick Clegg has said the Islamic State is "a challenge and threat" following the murder of British hostage Alan Henning.
Speaking on BBC's The Andrew Marr Show, the Deputy Prime Minister said it was "a very serious threat to our way of life that will last a very long period of time."
Disagreeing with comments made by former Chief of Defence Staff General Lord Richards, Clegg said, "I don't think it's a question of ramping up conventional armed forces again as if we were fighting state-to-state conflicts."
Nick Clegg said "of course we can" when asked if he could turn round the Lib Dems' fortunes before the General Election.
Clegg spoke as he arrived at the Lib Dem conference in Glasgow.
He posed with Baroness Sal Brinton, former MEP Liz Lynne, Linda Jack and Daisy Cooper - the four candidates vying to succeed Tim Farron as party president.
Nick Clegg has delivered a message to Islamic State, telling the organisation what they are doing is "sick and twisted" and they "will not win".
The Deputy Prime Minister said: "If you're doing this to intimidate us, you won't. If you're doing this to break our resolve, you won't. If you're doing this to drag us into a religious war on your terms, you won't."
Instead Britain will "play our role to hunt you down and to rid the world of this barbaric violence," he added.
Nick Clegg has condemned the "brutal murder" of British hostage Alan Henning "by an organisation that is twisting ... religion to its own ends."
The Deputy Prime Minister said his "heart goes out" to Mr Henning's family.
"He was obviously a good man trying to do good things," the Lib Dem leader said.
"He was trying to help people in Syria, he was trying to help the many Muslims who are suffering in Syria and he's now been brutally murdered by an organisation that is twisting that religion to it's own ends."
Deputy Prime Minister Nick Clegg has condemned the "barbaric actions" of Islamic State after the murder of Alan Henning, adding that the government is "resolved to defeat this evil".
Sincere condolences to Alan Henning's family. Barbaric actions of ISIL are held in complete contempt. We are resolved to defeat this evil.
Alan Henning was a man moved to selflessly help those most in need and we should remember that above all else at this difficult time.
Deputy Prime Minister Nick Clegg had the last word at the end of a six-hour debate in the House of Commons regarding air strikes in Iraq:
We must act. We do so mindful of the mistakes and lessons of the past, but we do so with lawful authority, with clear objectives and with the support of active participation of a broad coalition of international opinion which is saying to ISIL 'enough is enough'. And that is why, Mr Speaker, I commend this motion to the House.
Deputy Prime Minister Nick Clegg has tweeted:
It's right that parliament is recalled for MPs to debate UK response to Iraqi Gov request for support in fight against ISIL
Communities and Local Government Secretary Eric Pickles has cautioned against calls for the creation of powerful new combined local authorities centring on big cities, after Nick Clegg called for more devolution of powers.
Localism in England should be about devolving power to the lowest appropriate level - down to councils, to neighbourhoods and to individuals.
There may be some role for combined authorities on a strategic level to promote economic development and transport, but there is a real risk they will suck power upwards away from local councils and local taxpayers.