The Government has come under attack for the way it introduced a new bursary scheme designed to help the poorest teenagers stay in education.
Ministers also faced criticism from the Education Select Committee over the way the Education Maintenance Allowance (EMA) was scrapped.
The EMA, a weekly payment of between £10 and £30 given to the poorest teenagers to help them stay in education, was controversially scrapped by ministers earlier this year.
In a new report on 16 to 19-year-olds in education an training, the cross-party group of MPs said a change to financial support for this age group was "inevitable".
The report says it is difficult to assess the benefits and improvements in pupils staying in education due to the EMA, but adds: "We would have welcomed a more measured and public analysis by the Government before it took the decision to abolish the EMA.
"The Government should have done more to acknowledge the combined impact on students' participation, attainment and retention, particularly amongst disadvantaged sub-groups, before determining how to restructure financial support."
The Committee also raised concerns that over the way a new bursary scheme, designed to replace the EMA, was introduced.
The Government allocated funding to teenagers for 2011/2012 far too late to allow these youngsters to make informed decision about their education, the report said.
"Allocations of funding for student support through the bursary scheme for 2011-12 have been made far too late to allow Year 11 students to make fully informed decisions on what they will do the following year.
"The Government misjudged the scale of support necessary when announcing the abolition of the EMA, and precious months were lost while it revised its plans and consulted on the bursary proposals.
"The delay in deciding on allocations and guiding principles for distribution was regrettable and should not have been allowed to happen."
It also warns that it will be "difficult" to make sure that funding goes efficiently to those in need.
The report also notes that more teenagers are staying in education beyond compulsory school age.
In most schools there are 12- and 13-year-olds who are unenthusiastic about "academic" learning.
It recommends that "the Department should consider whether a 40%/60% split between time spent on specifically vocational or technical study and on a core academic curriculum would best suit 14-year-olds who take up vocational options while at school".
Committee chairman Graham Stuart, Conservative MP for Beverley and Holderness, said: "Young people taking life-defining decisions at 16 need clear information on the support they may receive and deserve better than rushed and ill-thought-through reforms.
"We accept that changes and savings need to be made but the organisation of the change has been far from smooth. Decisions on how much will be available for distribution by each school or college have been taken far too late, and it is 16-year-olds who have suffered uncertainty as a result. That should not have been allowed to happen."
Sally Hunt, general secretary of the University and College Union (UCU) said: "We are pleased the select committee has acknowledged the complete mess the Government has made of the EMA.
"Ever since the government started cherry-picking research to drive through the end of the EMA, it has been clear to us that thousands of the country's poorest teenagers would suffer."
A DfE spokesman said: "We have always been clear that we will not allow financial issues to be a barrier to young people staying on at school or college post-16.
"We are pleased to see that the committee acknowledges the Government's rationale for closing the very expensive and centralised EMA scheme.
"This decision was made based on thorough analysis of all the available evidence and we have worked with representative bodies such as the Association of Colleges throughout this process.
"We firmly believe that a more targeted approach is needed and it is right to put money in the hands of heads and college principals, who know their pupils best. This is precisely what the new bursary scheme will do."Reuse content