Ministers are inviting all schools in England to become academies, as long as they team up with a strong school.
Good schools with outstanding features will also be automatically approved, as outstanding schools are now.
Teaching unions said the scheme had become confused, as schools had already been invited to apply, with no mention of a requirement to form partnerships.
The government says more academies, which operate outside local authority control, will raise standards.
The coalition government has been pushing the roll-out of the programme, which gives schools more freedom over their budgets and curriculum.
But critics say that an increase in the number of academies will weaken co-ordination at local authority level and lead to a fragmented education system.
Academies gain access to funds which would previously have been pooled at local authority level for area-wide services such as special needs provision.
"Many more schools will now be able to become academies and I am pleased they will be able to enjoy the additional freedoms, responsibility and empowerment that comes with academy status," said Mr Gove.
"We know that the best way of improving schools is by getting the professionals who have already done a brilliant job to spread their wings," Mr Gove said, referring to the plan to encourage schools to form partnerships.
Later, Prime Mister David Cameron said he was "fantastically excited" about the academy programme, and that the government had put "rocket boosters" under it.
But shadow education secretary Andy Burnham accused the government of "dismantling" state education.
He said the government's schools reforms were "a free market experiment brought in at break-neck speed with scant supporting evidence".
Wednesday's announcement follows Education Secretary Michael Gove's warning to local authorities that he was ready to use his powers to force struggling schools to become academies.
The Academies Act, passed in July, made it possible for all schools to apply to become academies.
In May, Mr Gove wrote to all schools inviting them to register their interest - although the Department for Education said all schools had been "invited to apply".
However, on Wednesday it said schools other than those rated "outstanding" by the schools watchdog Ofsted have not actually been able to apply until now.
Christine Blower, General Secretary of the National Union of Teachers, said the academies project was "quite obviously in total disarray".
"The various announcements and mixed messages coming from Michael Gove about who can and cannot apply for academy status is both bewildering and of great concern," she said.
Ms Blower also said that schools could work together to share best practice and resources without having to become academies.
Chris Keates, General Secretary of the NASUWT teachers' union, said "only a handful" of schools had become academies, and most of those were doing so because they would gain financially.
She warned schools against converting at a time of change in the the schools funding system, and reports that a new government body may be created to oversee a shake-up.
"It would be foolish to take the profound and irreversible decision to sever any link with a local authority and put their schools at the mercy of a remote, national, democratically unaccountable funding quango," she said.
However, the Association of School and College Leaders said that opening the programme to all schools would "help to create a more level playing field".
"When academy status was only available to a few schools, there was the potential to create a fragmented education service," said general secretary Brian Lightman.
Critics have said the programme so far has been likely to primarily benefit schools in privileged areas, where outstanding schools tend to be located.
For the first time special schools will also have the opportunity to become academies.
Officials say this will give them more flexibility in how they buy in support for pupils' special needs.
There are about 21,000 schools in England and currently 347 of them are academies.
Eighty of these are the new-style academies, created since the coalition came to power and altered the scheme, which under Labour had targeted support towards deprived areas.
Since July some 224 applications for academy status have been received by the Department for Education.