Struggling free schools have been earmarked for special fast-track attention by the government because of the potential for serious political embarrassment for education secretary, Michael Gove, if they should fail, according to leaked documents seen by the Observer.

Marked "Official – Sensitive", the confidential papers warn that the "political ramifications of any more free schools being judged inadequate are very high and speedy intervention is essential".

Gove's flagship policy of allowing groups to set up schools outside the supervision of local education authorities has been the subject of a barrage of bad publicity in recent months. Four free schools have been declared inadequate by Sir Michael Wilshaw's Ofsted, with one of those, the Discovery New School in Crawley, West Sussex, closing down last week.

The leaked document shows that the Department for Education wants to tackle the problems at inadequate free schools before their failings are made public by Ofsted, at which point they can be used as political ammunition. It suggests that party political considerations are now driving education policy a year ahead of the general election, provoking one union leader to claim that the public would be "appalled".

The revelation is in a 40-page document prepared for academies minister Lord Nash ahead of a meeting on 19 March with senior civil servants at the department for education. In the document, which deals with the accountability of free schools and academies, it is proposed that ministers will monitor free schools through private education advisers and be responsible for making key early decisions on tackling problems because of the risk of major political fallout further down the road.

In contrast, turning around failing community schools is often a protracted process requiring Ofsted to make a ruling that they are inadequate before concerted action is taken. Around 350 such schools have been in special measures for more than a year.

The document, entitled Future Academy System: Lord Nash session, also highlights problems that new free schools are facing, despite ministers' public stance being that the programme is proving a success. It says: "Experience has shown us that free schools in their first years of operation are different from other open academies, and face problems that are often not educational in origin.

"These often include operating in temporary sites without a clear permanent home; new, inexperienced and often isolated trusts needing to upskill themselves to run a school for the first time; instability in principal appointments and senior leadership teams."

Chris Keats, general secretary of the teachers' union, the NASUWT, said: "Parents and the public in general will be appalled. I have long said that Michael Gove is the secretary of state for free schools and academies, not a minister for education. This is what the government is focused on – and now it has been put in writing."

Shadow education secretary Tristram Hunt said he was dismayed by the document and called for Gove to focus on "what really matters". He added: "This is more evidence that Michael Gove's exclusive focus is on a free school project for around 2% of pupils. We now know that because of the huge political embarrassment caused by damning Ofsted judgments of his flagship free schools, he is signalling that he wants even more resources dedicated to trying to save him further embarrassment."

Just 38 free schools out of the 174 opened so far have been Ofsted rated. Six are outstanding, 21 good, eight require improvement and four have been found inadequate.

The leaked document also spells out how a new supervision regime for academies, including established free schools, will work when eight regional school commissioners (RSCs) take on decision-making roles in August for primaries and September for secondaries.

To emphasise the importance of the new system, under which the RSCs will decide who will sponsor academies among other duties, it notes that in the East Midlands and the Humber region, there are 600 academies, 136 of which are underperforming.

It also reveals the existence of an internal DfE grading system for the sponsors of academies, such as AET, Harris and Greenwood Dale. It reveals that of the 72 sponsors in the new "north-east London and east region" set to be monitored by a regional commissioner, 71% are in the two worst categories out of four.

Nationally, the document notes: "Ofsted have started inspecting academies in sponsor batches – this may increase the number of sponsor underperformance issues (eg E-Act) and RSCs will need to work closely with each other and with ministers to deal with particularly severe issues."

E-Act, one of the largest chains of primary and secondary academies and free schools in England, was lambasted last month by Ofsted inspectors who placed five out of the 16 E-Act schools it inspected into special measures. They included Hartsbrook in Tottenham, north London, one of the government's flagship free schools.

The document adds that a risk of the new regime, under which DfE powers are delegated to RSCs, is that "more people will be aware that out intervention powers are pretty weak".

A DfE spokesman said: "We do not comment on leaked documents. We have consistently demonstrated that where we find failure – whether in council-run schools, academies or free schools – we act quickly and decisively. The vast majority of free schools that have been inspected so far are performing well. In the last month alone Dixons Trinity Academy and Reach Academy have been rated outstanding by Ofsted despite opening only 18 months ago, and five more have been rated good."