MAJDA 03:
With a student visa you can work only 20 works per week (part-time) and only during vacations you can work full-time.
You cannot work after you complete the course unless you work at the STUDENT'S UNION. You can also work ONLY if the work placement is part of your course and if the work placement is an assessed part of the course.
Here its what it says literally about any other type of work in the UK with an adult student visa: (PAGE 13, POINT 54-63)
TYPES OF STUDY AND WORK PLACEMENTS
Student union sabbatical officers
54. A student union sabbatical job is a full-time, salaried, elected executed union position. You may take this job during your studies or in the academic year inmediately after you graduated.
55. If you take the job while you still have time left in your permission to stay as an adult student, your approved education provider must let us know as they are responsible for you until your permission to stay runs out.
56. If you want to do the job at the end of your course, AND YOU HAVE NO MORE TIME LEFT IN YOUR PERMISSION TO STAY AS A STUDENT, you must apply again and emet the requirements of the category.
57. A sabbatical job is normally for one academic year and you may be given permission to stay as an adult student to cover this time. If you are re-elected after one year, you will have to apply again. You can only have the job for a maximum of two years.
WORK PLACEMENTS
61. You will be allowed to do a work placement as a part of your course of study, as long as the work placement is an assessed part of the course and the course is at an acceptable level for adult of child students.
The work placements must be no more than 50% of the lenght of the course in the UK. An example is if a course is two years long and the first year of the course involves full-time study, with the last year in a work placement.
HOPE THIS HELPS! BUT WELL NO, YOU CANNOT WORK AFTER YOU GRADUATE WITH THE STUDENT VISA UNLESS YOU WORK AT THE STUDENT UNION OF IF THE WORK PLACEMENT ITS AN ASSESSED PART OF YOUR COURSE OF STUDY. IF THE TIME LEFT ON YOUR STUDENT VISA HAS PASSED YOU HAVE TO APPLY FOR THE VISA AGAIN.
My interpreation of the Tier 4 guide:
I think that work placement which forms a part of your course assement and other work are dealt with separately.
Work place is restricted to up to 50% of the total length of your course.
Other work is limited to 20 hours per week during term time and full time during vacations. This work must exclude filling a permanent full-time vacancy, self-employment and a few other things -- therefore temporary work is allowed.
The adult student visa for a 12 month course allows you to stay an additional 4 months after completion of the course (2 months after completion of a 9 month course). If this 4 month extension is considered vacation time, you may be able to work full time during this period.