Webb scored a considerable victory when he organised a successful strike in 1908 at a mine in Blackball, and became prominent in the labour movement nationally.

Many of the older leaders continued to support the loose alliance between the labour movement and the Liberal Party, but Webb believed that only independent action could advance workers' interests.

Webb was involved in founding the radical New Zealand Federation of Labour (the "Red Feds"), and in the 1911 election, he stood unsuccessfully in the Grey electorate in Parliament.

In order to seek a public mandate for his decision, he resigned from his seat in Parliament, and challenged the government to fight the by-election on the issue.

[3] When the Labour Party won the 1935 general election, Webb was appointed to Cabinet by Michael Joseph Savage, his old friend from the mines in Australia.

Gradually, assisted by the heightened demand for coal during World War II, Webb oversaw the purchase of many major operations.

Webb had a reputation as Parliament's Lothario, and in mid-1939 he was being pursued by a woman for breach of promise to marry; the Hon Mark Fagan got Colin Scrimgeour then the head of commercial broadcasting to give her a job with radio station 1ZB in Auckland.