Whilst all of the men were away fighting, and all of the women were working in the factories, and every other job that had been left vacant, the suffragists were still quietly campaigning.
It could possibly have been because whilst the suffragettes had temporarily given up their campaigning in favor of the war, the suffragists had time and space to move forward in their campaign.
Before the war, women did have jobs, just not the same jobs as men. Women were servants and dressmakers and suchlike, they did not handle heavy materials etc. When the men went away to war, they proved that they could, and would. At the end of the war, women were doing jobs such as shipbuilding, grave digging, bus drivers and steel workers. Many men felt threatened and resented the women, but this was mainly in certain, extremely masculine circumstances. Most places welcomed women, as they were incredibly short of workers.
Women favored working in the munitions factories most of all. It was dirty and very dangerous and turned their skin a yellowish colour. Due to the demand for bullets and ammunition, the factories were expanded and most of the workers were female.
When the war ended, however, the women had to go back to their previous jobs, as the men returning from war wanted theirs back. It seemed that nothing had changed, and during the war, the women were only there, as the employers had no choice but to employ females. Men tried even harder to protect their jobs, too, as women were usually prepared to work for lower wages.
In 1916, the government decided that they had to change the voting system. Only men living permanently in the UK could vote, and as most of the men were abroad fighting for their country. The government revised the voting system, and the campaigners took the opportunity to push the government for the vote. Therefore, the war had a major effect in that respect on how women were perceived.
Another element in the decision would have been the fact that men and women spent so much time together that the “rules” between men and women were demolished. They no longer required a chaperone, women started visiting pubs, and the illegitimacy rates had increased 30% by the end of the war.
In conclusion, I think that if WW1 did not happen, women would not have got the vote when they did; it definitely helped a great deal.