David Cameron will call today on public sector unions to halt planned industrial action and accept that their pension packages are unsustainable and must be reformed.
The Prime Minister will insist the present arrangements are "not fair to the taxpayer" two days before a mass walkout of teachers, lecturers and civil servants.
The Government is finalising contingency plans to deal with the biggest outbreak of industrial action since the coalition was formed, with up to 750,000 workers set to stage a 24-hour walkout on Thursday.
The stoppage, by members of four unions, will go ahead despite two hours of talks yesterday between ministers and union leaders to try to resolve a bitter row over pensions.
With talks due to resume in July, Mr Cameron was reported to have prepared a "robust" but fair message to unions in a speech to the Local Government Association annual conference.
The scale of the disruption will become clearer today as schools decide whether to close and parents learn if they have to make alternative arrangements for their children.
The TUC welcomed moves by the Government to meet again in July after ministers said they recognised that the funding basis for the scheme covering local government workers was different.
But Mark Serwotka, leader of the Public and Commercial Services union, described the talks as a "farce", accusing the Government of having no interest in negotiating on plans to cut pensions, extend the retirement age and increase contributions.
Mary Bousted, leader of the Association of Teachers and Lecturers, said: "We are disappointed, but not particularly surprised that the Government has yet again refused to give us the information we need to carry out negotiations about teachers' and lecturers' pensions."
Cabinet Office minister Francis Maude and Chief Secretary to the Treasury Danny Alexander maintained that the meeting was constructive and expressed disappointment that Thursday's strike was going ahead because talks were ongoing.
"We can assure the public that we have rigorous contingency plans in place to ensure that their essential services are maintained during the strike."
The National Association of Head Teachers said it had "grave concerns" about a suggestion by Education Secretary Michael Gove that parents could volunteer to cover for striking teachers.
General secretary Russell Hobby said: "It is probably not unlawful but we would strongly advise our members not to accept voluntary help to cover for absent staff this Thursday."
In a joint statement, Mr Maude and Mr Alexander said: "We believe both sides have a responsibility to see the talks through and we would urge public workers not to strike while they are ongoing.
"Public sector pensions will still be among the very best, with a guaranteed pension which very few private sector staff now enjoy.
"We are proposing they will be paid later because people live longer and that public sector staff will pay more, for a fairer balance between what they pay and what other taxpayers pay."
The ministers said they recognised that funding for the local government scheme was different and agreed to have a "more in-depth" discussion, which was welcomed by Unison leader Dave Prentis, who said the Government was treating the negotiations seriously.
Unison will await the outcome of two further meetings in July before deciding whether to press ahead with a ballot for strikes which involve more than a million workers.
TUC general secretary Brendan Barber said that some progress had been made on some of the issues, but there was still a "major gap" between the two sides on plans to increase the pension age, raise contributions and change the way pensions are determined from RPI to CPI inflation.
"The Government did enter into some movement on some issues and there will be a further meeting in July. This is a serious process which we are committed to, because we want to try to reach an agreement."
Mr Serwotka said: "On Thursday we will see hundreds of thousands of civil and public servants on strike and, on the experience of today's meeting and the last few months of Government obstinacy, we fully expect to be joined by millions more in the autumn."
Christine Blower, general secretary of the National Union of Teachers, said: "The Government has done nothing more today other than confirm it has no intention of listening to teachers. They are simply imposing draconian changes that will see teachers paying more, working longer and getting less with no evidence to back up these claims.
"The action on Thursday is unavoidable and unless the Government starts listening rather than simply imposing its will, it leaves us with little choice other than to consider further action."
University and College Union general secretary Sally Hunt said: "We remain committed to a negotiated solution to the pensions row. However, it is incredibly disappointing that the Government does not seem to share that desire.
"The average lecturer faces an increase of around £90 a month in exchange for reduced benefits. Women who teach in further education retire on an average pension of just £6,000 a year, yet the Government wants the public to believe they are on gold-plated schemes."
Brian Strutton, national officer of the GMB union, said: "The talks made progress in several important areas and I'm particularly pleased that Government has recognised the unique position of the local government pension scheme (LGPS).
"I've been arguing for some time that the LGPS needs separate negotiations and Francis Maude and Danny Alexander agreed to hold independent discussions with us about the LGPS. This gives us the opportunity to secure a sustainable future for the £150 billion LGPS funds which members have invested for their retirement."
Picket lines will be mounted outside schools, colleges, universities, Parliament, courts and government buildings such as the Treasury on Thursday, with many workers going on strike for the first time.