The Police Act of 1919 was the death knell of NUPPO. It established the Police Federation of England and Wales, a public sector version of a company union, to replace NUPPO. Under the Act, NUPPO was outlawed as a representative body for the police and forbade police from belonging to a trade union. NUPPO had no options but to fight or fold; unsurprisingly, it chose to fight. This time, however, it was the union that misread the mood of the men when it called for another strike. Out of a force of 18,200 men in the Metropolitan Police, only 1,156 participated in the strike in 1919.