The coalition is heading for a potentially damaging split on education as Liberal Democrats prepare at their conference next month to urge parents not to send their children to Michael Gove's flagship free schools, describing them as "socially divisive, likely to depress education outcomes and an inefficient use of resources in an age of austerity".

The move will be the lead education motion at the conference. Published today, the motion warns that such schools will add to "the multiple tiers and types of schools created by successive Conservative and Labour governments, and thus abandon our key goal of a high quality education system for all learners".

The schools motion urges the coalition to revise its support for academy schools, warning that local authorities should retain oversight of places in all schools in receipt of any state funding.

Lib Dem concern over the impact on inequality of spending cuts is also expressed in other motions published today.

The party conference in Liverpool, the first the Lib Dems have held while in power, is expected to draw up to 6,000 people and will be watched with a degree of seriousness not usually attached to the proceedings of the third party of politics.

Nick Clegg, the deputy prime minister, is expected to receive a hero's welcome despite the party's recent slide in the opinion polls, but will be leaving the conference early to attend the United Nations conference on the millennium development goals in New York. The party is particularly losing support in the north and among young voters.

Although unease will be expressed on the conference fringe over the direction of the coalition, and over specific policies on the main conference floor, senior party figures believe the mood will be upbeat.

In a sign of nerves at the impact the austerity programme may have on the party's commitment to fairness, one motion also calls for the Office for Budget Responsibility to be made truly independent, and for its remit to include assessing the socio-economic impact of Treasury policy, as stipulated in the Equality Act 2010.

It also calls for ministers to be "given freedom and resources to commission research to fully assess the viability and practicality of increasing taxation on wealth – including land values".

The conference will demand tighter terms of reference for an inquiry into British involvement in US torture of alleged terrorist suspects. The motion claims the purpose of the inquiry will be undermined if the findings are not made public.

It is also due to call for a shake up of the Press Complaints Commission with the removal of senior editors from the PCC board, in line with the recommendations of a recent inquiry by the culture and media select committee. The motion says "a regulator should be entirely independent of serving editors, and should have the power to take disciplinary action, including financial penalties, against editors who breach the code".

The culture committee investigated complaints that Andy Coulson, No 10 director of communications, had been aware of illegal phone interception when he was News of the World editor. The select committee found the PCC had not investigated the allegations with sufficient seriousness, which the PCC disputes.

A motion broadly supporting the direction of the coalition's energy policies warns against "changes to the carbon price that result in windfall benefits to the operators of existing nuclear power stations". Energy secretary Chris Huhne again promised today there would be no hidden or clear subsidy for nuclear power.

Disagreements over coalition education policy could be the most contentious individual policy issue. The motion says free schools create surplus places prejudicial to efficient use of resources. It suggests they will increase social divisions "when all efforts should be focused on improving educational outcomes by enabling effective teaching and learning to take place in good local schools accessible to all".