Section 17B1/2. No mortgagee who makes a loan to a first-time home loan borrower, to be secured by a mortgage on owner-occupied, 1 to 4 family residential property in the commonwealth, shall make a subprime loan at a variable or adjustable rate of interest unless the mortgagor affirmatively opts in writing for the variable or adjustable rate subprime loan and receives certification from a counselor with a third-party nonprofit organization that the mortgagor has received counseling in person on the advisability of the loan transaction; provided, further that said third party nonprofit organization shall have been approved by: (1) the United States Department of Housing and Urban Development; (2) a housing financing agency of the commonwealth; (3) the Massachusetts Homeownership Collaborative; (4) or the regulatory agency which has jurisdiction over the mortgagee. The commissioner of the division of banks shall maintain a list of approved counseling programs. At or before closing such a loan, the mortgagee shall obtain evidence that the mortgagor has completed an approved counseling program. If such subprime mortgage loan is made by a mortgagee in violation of this section, the variable or adjustable rate terms of the loan shall not be enforceable and the mortgagee shall only be entitled to collect an interest rate equal to the lesser of the original interest rate, including any discounted rate, or the current adjusted interest rate throughout the remaining term of the loan. The commissioner of banks shall issue directives or guidelines or adopt regulations to administer and carry out this section and to further define the terms used in this section.