Which company rejected a job application from Margaret Thatcher stating she was "headstrong, obstinate and dangerously self-opinionated"?

Margaret Hilda Thatcher, Baroness Thatcher, (née Roberts; 13 October 1925 – 8 April 2013) was a British stateswoman who was Prime Minister of the United Kingdom from 1979 to 1990 and Leader of the Conservative Party from 1975 to 1990. She was the longest-serving British prime minister of the 20th century and the first woman to have been appointed. A Soviet journalist dubbed her the "Iron Lady", a nickname that became associated with her uncompromising politics and leadership style. As Prime Minister, she implemented policies that have come to be known as Thatcherism.

Roberts graduated from Somerville College, Oxford, with Second-Class Honours, in the four-year Chemistry Bachelor of Science degree. She then moved to Colchester in Essex to work as a research chemist for BX Plastics near Manningtree. In 1948 she applied for a job at ICI, but was rejected after the personnel department assessed her as "headstrong, obstinate and dangerously self-opinionated". Professor Jon Agar had explored her career in chemistry and argued that her understanding of modern scientific research impacted her views as Prime Minister.