In British history, which group of people was primarily affected by the "Cat and Mouse Act"?

Technically termed the "Temporary Discharge for Ill Health Act", but generally known as the "Cat and Mouse Act"; this legislation was enacted in the United Kingdom in 1913, under the Liberal government of Prime Minister Herbert Asquith (1852-1928). Those most affected by it were members of the campaign for votes for women, often called Suffragettes or Suffragists.

It was couched as a humanitarian act. Many of the women had gone on hunger strike, and been subject to the harrowing and even potentially fatal ordeal of force feeding. Although it may have contributed to the lessening of this practice, it also served to make many women spend far more time in prison. They might not be force fed, but were released only when they had reached a state of extreme weakness, only to be readmitted the instant their health allowed it, or on the commission of any further offences, no matter how minor. The act took its name from the supposed habit of domestic cats of playing with their prey before finally pounding.

It appears that, like force feeding before it, the Act did little to quell the determination of the campaigners, but it is hard to make a subjective judgement, as soon after it passed the First World War broke out, and many, though not all, put their protests in abeyance, and soon after the war ended, women were granted the vote, though at first only those over 30.