Angry parents have blasted an Ipswich sixth form for “damaging” the education of students with learning difficulties after cutting their classroom time by nearly a half.

Dozens of families have hit out at a decision to slash foundation learning courses – aimed at pupils with profound or moderate learning difficulties – from five days a week to three at One, formerly known as Suffolk One, in Ipswich.

They argue the overhaul is unfairly penalising vulnerable children and criticised the timing of the “bombshell” news, claiming it “came out of the blue” and just a week after the deadline passed for applying for places at dedicated special schools.

They accused the Scrivener Drive college of failing to “accommodate the requirements of the statutory statements” of foundation students and said legal action is being considered.

However officials at One refuted these allegations. They said the college will match other post-16 colleges in providing foundation learning over three days and insisted students affected by the move will still have a full-time education consisting of more than 540 hours of teaching and support.

The controversial move, taking effect in September, could claim the jobs of 13 full-time staff members at One.

One insists all 11 foundation learning courses will remain. They include English and maths as well as independence skills and performing arts. Some 15 parents and carers of foundation stage pupils attending – or due to attend – One signed a letter sent to the Star. More than 50 people now endorse it.

It said: “The emotional costs to our children of this reduced offer is enormous. To us as parents it is catastrophic. The impact to us as families of lost income from having to lose two days a week at work…will plunge us into poverty and lead to us becoming more reliant on state support.”

It added: “We were told that the change was justified because our children get too tired – ‘five days is often too demanding for students’.

“This is a huge generalisation about disability which you would expect from the ‘medical model’ of disability from the 1950s. It is not true. Most of our children thrive on the stimulation. These cuts are not in the interests of their wellbeing.

“This announcement was made shortly after the closing date for applications to other special school sixth forms in the area and has left our cohort of parents with very reduced options for requesting a placement elsewhere.

“Throughout all the open evenings and transition sessions our children attended at One no mention was made of the impending changes and, to receive the news out of the blue, was a great shock to them and to us.”

The letter was penned by Sue Edwards. Her 16-year-old wheelchair-bound son Jake was set to start at One in September and the family is now considering legal action.

Pat Kerridge adopted Ashley Kerridge, 17, when he was three weeks old. She said his education will be severely hampered by the change but insisted she will “fight tooth and nail” for him.

“It is diabolical – they are being penalised for being different,” said the 61-year-old, of Hasketon, near Woodbridge.

“They learn at a different pace and need to read and write every day for it to sink in because they don’t have a long-term memory. With four days off, they will forget everything.

“They need social interaction and a routine, especially children with autism. It was a bombshell by letter and will damage their education. There was absolutely no consultation at all and I am very angry.”

Caroline Rudd, of Felixstowe, said it will be difficult to explain the decision to her 17-year-old daughter and One pupil Ella Rudd, who has cerebral palsy and is registered blind.

“It is crazy. They are not interested in the effect it is going to have on vulnerable children,” she added.

Ipswich MP Ben Gummer said: “It is a very complicated situation but there is a simple truth at its heart which is that all children, no matter what they are learning are entitled to a full education till the age of 18.

“This week I should be speaking to the principal, the county council and the minister to see what can be done to sort out this situation. I am determined to do what I can to make sure that happens.”

Alan Whittaker, principal of One, said: “In October 2013 we outlined our proposals to the county council. Due to the nature of this very difficult decision we needed to allow sufficient time to explore all options before publishing the rationale for change.

“All students at One are able to access the resources and facilities at One outside of taught classes, what we cannot provide is supervision or specific support to any students during non-timetabled sessions.

“The timetable will be agreed once the new faculty head is in post but there will not be a reduction in the number of subjects taught.

“We have met with parents who have asked to meet with us on a one-to-one basis and we have met with the county council and will continue to do so. We have a representative from One on the county council working party who are looking at alternative provision for the two days when students are not at One.

“The only way in which we can remain an inclusive college able to offer a range of opportunities to all is by adopting this new model consistent with other Post 16 providers.”

A spokesman for One added: “We accept that we are not a college of further education – however the point relating to the fact that One ‘has failed to accommodate the requirements of the statutory statements of foundation students’ is not true.

“Statements for foundation learning students at One state that the individual should be entitled to full time education – full time education as defined by the Department for Education is a minimum of 540 hours of teaching and support, the current and new model will still be in excess of this.”

He added: “The principal has been fully involved in this situation throughout. However, The vice principal – as part of her roles and responsibilities – has taken the lead in terms of all communication with parents and carers during this situation, whether that be on a one to one basis, via emails, telephone calls or letters.”