Pearson, the exam board in charge of BTecs, knew from July that results could be delayed, the chairman of the education select committee has said.
Pearson and others will be quizzed by MPs about why many students are still missing grades, Robert Halfon said.
He suggested exam boards should refund schools, which pay for students to enter exams, if issues are not solved.
Level 2 and 3 BTec results will be included in a review into the delays by Ofqual, England's exams regulator.
The Level 2 results – for about 235,000 BTec Firsts, Technicals and Tech Awards – were meant to come out on Thursday alongside GCSEs in England, Wales and Northern Ireland.
But on Thursday, Pearson warned that 5,700 students would not be receiving theirs.
This may be because of processing issues, the BBC understands. In other instances, it may be because the pupil has dropped out before the end of their course.
Last week, Pearson also apologised to students taking Level 3 BTecs – a similar standard to A-levels – after some faced delays in getting their results, throwing their university places into doubt.
Other students are waiting on results for Cambridge Nationals, issued by the OCR exam board.
Emma Harrison, who is 18 and from Stratford-upon-Avon, was supposed to receive results for her Level 3 BTec in health and social care last Thursday.
But her results were delayed – meaning she did not know if she would be able to take up her place on a mental health nursing course at the University of Worcester.
"I was seeing loads of my friends receiving their results," she says.
"It just felt that yet again, BTec was second place to A-Levels."
She said she called Pearson "numerous times", but it was only after her dad called later than she was sent her grades.
"It was extremely frustrating, it just felt like they didn't care," she says.
Her university place was confirmed a week later, but she says the celebrations "have been ruined".
"It feels like everyone's passed it now that I have my results," she says.
"But it is a relief. It feels like the hard work I put in has paid off."
In an interview with BBC Radio 4's Today programme, Mr Halfon said he had met with Pearson and told them the delays were "unacceptable".
"They knew this problem from early July, because there were delays from some school results," he said, adding that "there should be no reason for this delay".
Schools and colleges pay exam boards when they enter students into qualifications.
Mr Halfon said delays to BTec results had "happened before", and that if exam boards "don't get their act together, they should look at their funding being refunded".
"We're going to call Ofqual and these organisations – Pearson and others – to our education select committee and ask questions to make sure we don't just have this again next year," he said.
He added that politicians would be "up in arms" if delays were with A-levels or GCSE results.
An Ofqual spokeswoman said: "We will examine all relevant information to better understand what has happened and what needs to change to ensure that students are protected.
"Should we find the awarding organisations have been at fault, we will consider what action, including possible regulatory action, is appropriate."
Pearson said on Thursday that about 790 students had still not received results for their Level 3 BTecs, and 5,700 had not received their results for BTEC Firsts, Technicals and Tech Award qualifications.
On Friday, a spokesperson said Pearson was continuing to work with "a handful of schools and colleges" to review whether students currently marked as being "ineligible" for a result are in fact eligible.
They added the situation "has been very difficult for students and their families" and that the exam board would conduct its own review – in addition to Ofqual's – to work out how to improve the system in future.
OCR said on Wednesday it was "well on the way to issuing the remainder" of missing Level 1 and 2 Cambridge National results.
Tom Middlehurst, of the Association of School and College Leaders, said the union had not heard of students being unable to move on to post-16 courses, because many Level 2 BTec students also study other qualifications, which they will have received on Thursday.
"Nevertheless, it is a deeply frustrating situation for these young people, and we need to ensure that lessons are learned so that this does not happen again in the future," he said.
Additional reporting Hayley Clarke.
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