If the worst thing happens that be imagined; if the worst possible thing happens; if troubles grow worse. If worst comes to worst and Mr. Jones loses the house, he will send his family to his mother's farm. If worst comes to worst, we shall close the school for a few days.
IF WORST COMES TO WORST
Meaning of IF WORST COMES TO WORST in English
American idioms English vocabulary. Английский словарь американских идиом. 2012