Paul Mackney will fire a broadside in defence of adult education in his final speech as general secretary of the college lecturers' union this weekend.
It will be Natfhe's final conference before its merger with the Association of University Teachers.
Mr Mackney has already announced he will not be standing for the leadership of the new organisation, though he will be joint general secretary for an interim year.
He will support the National Institute of Adult Continuing Education's call for the wider education role of colleges to be protected as the Government focuses on vocational education as the main function of FE.
In his speech, he is expected to back Alan Tuckett, the director of Niace, in his call for a further education system focused on "creating and sustaining cultural value": improving students' quality of life as well as meeting the needs of their employers.
Niace has evidence that pensioners, for instance, are becoming increasingly less likely to sign up for courses as a result of the Government's change of emphasis.
Mr Mackney told FE Focus his parting shot will be a criticism of the "seven deadly sins" of the review of colleges carried out by Sir Andrew Foster, former head of the Audit Commission, which resulted in the Government'
recent white paper on FE.
The speech will also criticise Sir Andrew for failing to highlight the issue of funding of colleges, which continue to get an estimated 13 per cent less than schools for the 16 to 19-year-olds that they educate.
Mr Mackney pinpoints six more failings of the report, and will say it:
* "largely ignored" adult students in its focus on vocational training;
* failed to recognise that FE was about the wider educational needs of people beyond preparing for work;
* failed to recognise success;
* reflects the "idiot wind of Government ideology" by introducing the concept of "contestability" into the debate;
* confuses the short-term interests of employers with the long-term needs of employment, and;
* fails to address the pay of lecturers.
The new University and Colleges Union will be the world's largest post-16 education union. The merger, to take place on June 1, was backed by 95 per cent of Natfhe members who took part in the ballot, and 79 per cent of AUT members.
The enlarged union will represent 116,000 people, with former Natfhe members making up nearly 60 per cent of the total.
Paul Mackney has been in favour of merger since he was elected in 1997.
Sally Hunt, general secretary of the AUT, and Roger Kline, head of Natfhe's universities department, are standing for election as general secretary of the new union.
Meanwhile, a new Niace study says older people are being driven away from adult education as the Government focuses attention on the under-25s.
Its annual participation survey shows the proportion of people over 75 who have recently taken courses has fallen by a third to just 10 per cent.
Student numbers among adults aged between 25 and 54 are also falling, but at a slower rate.
The survey comes as the Conservatives criticised the Government's narrow focus on under-25s. David Cameron, the Tory leader, told a conference earlier this week: "At the moment, the training and further education budget in this country is firmly skewed towards the under-25s, and that is something that we believe ought to change."
Bill Rammell, the further education minister, said that, despite the changed priorities, there were still far more people in adult education today than nine years ago.
"We have increased funding by almost 50 per cent in real terms," he said.
"I don't want to make a crude party political point, but I will: there was a 40 per cent real-terms cut up to 1997."
Overall, the survey found that the number of people who have had no education or training since school has remained static over the last decade, at about a third of the population.
But more people expressed a desire to learn, with 47 per cent likely to take up a course in the next three years, compared to 38 per cent 10 years ago.