The TES revealed last week that the Government's examinations watchdog wanted to reduce the time spent testing the Bard by 15 minutes.
The proposal is part of a revamp of national curriculum tests and, coupled with the plan to split up reading and writing papers, would have reflected more closely what happens in English lessons.
However, the Qualifications and Curriculum Authority's plan - described as "sensible" by some English teachers - was immediately rejected by ministers because it "sent completely the wrong signal" to pupils.
The swiftness of Ms Morris's response demonstrates Government sensitivity to accusations of dumbing down and criticism from traditionalists. In 1997, her predecessor, David Blunkett, also vetoed plans which could have threatened Shakespeare's special place in the testing regime.
Changes to the key stage 3 English test include a 75-minute reading test with three linked passages and a writing test of one hour plus 10 minutes planning, made up of two pieces. Pupils will be given a break in between the tests.