In a piece today on Comment is Free, Polly Toynbee writes:
As for these polls, just remember that the same voters who say they don't want Blair to go yet are the ones who give him satisfaction ratings twice as bad as when Mrs Thatcher was toppled
It's not the same voters 16 years on, of course, but more interesting is the "twice as bad" bit. Thatcher left on 22 November 1990, and MORI polls show that in a poll carried out between 15 and 19 November 1990 she had 25% satisfaction and 71% dissatisfaction (source).
Twice as bad as 71% disapproval? What's that, then, 142% disapproval? Actually, the latest MORI figures (same page as above) give Blair a 23% satisfaction rating, and 67% dissatisfaction.