National Debt 7. Mr. Allen Adams asked the Chancellor of the Exchequer what is the current level of the national debt. Mr. Biffen As at 31 March 1979, the outstanding national debt amounted to £86,885 million. 17. Mr. van Straubenzee asked the Chancellor of the Exchequer by how much the national debt increased between 1974 and 1979. Mr. Biffen Between 31 March 1974 and 31 March 1979 the outstanding national debt increased by £46,428 million.