The ideological bond between the Liberal Democrats and Conservatives will strengthen today when Nick Clegg describes the "big society" and liberalism as the same, and the two parties set out an agreed path to transform public services.

The joint six-point plan for public service reform, drafted by the decentralisation minister Greg Clark, will be published alongside today's localism bill.

The bill will grant new powers to local authorities and communities, decentralising power and putting in place the legislative tools to implement the Conservatives' big society project, under which volunteers and communities will take over control of services from the state.

In his foreword to the public service reform plan, Clegg, who has been under attack from some grassroots Lib Dems for being too close to the Conservatives, argues that both parties support the big society and a radical decentralisation of public services, even if they have used a different language to fight its cause.

He writes: "The prime minister has coined the phrase big society while the Liberal Democrats tend to talk about community politics or just liberalism. But whatever the words we use, we are clear and united in our ambition to decentralise and disperse power in our society and that shared ambition is one of the of the bonds that will keep our coalition strong."

He argues that "dispersing power is the way to improve our public services, and get the better schools and safer hospitals we want".

The localism bill will be put before parliament today. It proposes to give communities new rights to take over services, bid to buy local assets such as libraries, and pubs, and a right to force a referendum to veto excessive rises in council taxes. Laws will be changed to tackle flyposting, by allowing landlords who profit from it to be prosecuted, and rules will be changed to encourage more regular refuse collections.

The planning permission rules will be changed to give local neighbourhoods the chance to vote for or against some applications and measures will be enacted to introduce elected mayors in Birmingham, Bradford, Bristol, Coventry, Leeds, Leicester, Liverpool, Manchester, Newcastle, Nottingham, Sheffield and Wakefield. Referendums to approve the idea will be held in those areas in May 2012, with elections the following May.

The six-point plan probably represents the most succinct account of how the coalition's reforms in schools, hospitals, prisons, welfare and local government are seen inside Downing Street.

The six steps set out are to "lift the burden of bureaucracy, empower communities to do things their own way, increase local control of public finance, diversify the supply of public services, open up government to public scrutiny and strengthen accountability to local people".

Clark is responsible for reporting to David Cameron by summer 2011 on how each major public service is meeting these tests. He stressed that the agenda is not simply about handing power and control of finances to local government institutions, but also about handing power further down the chain to smaller groups, as well as setting up new institutions such as local police chiefs and stronger neighbourhood groups. Examples in the paper include neighbourhood planning, ending top-down inspections, free schools and the right of NHS staff to run social enterprises.

Clegg's description of the programme as an area that will keep the coalition strong will raise eyebrows amid increasing debate about whether his party will survive as a separate entity.

Sir John Major, the former Tory prime minister, told the Andrew Marr show yesterday that he believed the coalition could survive beyond the next election. A merger was not what either party was pursuing, but he added: "We are two separate but distinct parties that have come together for a fixed period of time – maybe this parliament, maybe longer, very possibly longer."

It also emerged at the weekend that Oliver Letwin, the Conservative policy chief based in the Cabinet Office, has started a round of meetings with Liberal Democrat backbenchers to develop a joint policy programme to take the two parties through to the next election.