The new government in Beijing was supported by Great Britain and the United States. Li Yuanhong, the last president with any legitimacy, was recalled to sit as president again on June 12, 1922; however, any cabinet member had to be cleared by Wu Peifu. By this time Wu's prestige and fame had far surpassed that of his former mentor Cao Kun, nominally head of the Zhili clique. This strained their relationship, although it did not result in a fracture of the Zhili clique. Wu tried to restrain Cao when the latter began political machinations for the presidency but ultimately could not prevent Cao from toppling the cabinet and impeaching Li. Cao then spent several months campaigning for the presidency and even openly declared he would pay $5000 to any parliamentarian who would cast a vote for him. This caused national condemnation against the Zhili clique but did not prevent Cao from being elected in October 1923. In 1923 Wu ruthlessly broke a strike at the important Hankou–Beijing railway by sending in troops to violently suppress the workers and their leaders. The soldiers killed 35 workers and injured many more. Wu's reputation with the Chinese people suffered significantly because of this event, though he gained the favor of British and American business interests operating in China. Although it appeared that Zhili's power was secure for the time being, a crisis in the south soon precipitated another showdown with the Fengtian clique. The crisis was over the city of Shanghai, the commercial powerhouse of the nation. It was part of the province of Jiangsu, under Zhili control, but actually administered by Zhejiang, ruled by the remnants of the Anhui clique. When the Zhili clique demanded the return of Shanghai to their administration they were refused and fighting soon broke out. Zhang Zuolin in Manchuria and Sun Yat-sen, then in Guangdong, quickly declared their support for the Anhui clique and geared up for war. Wu Peifu dispatched his subordinate and protégé Sun Chuanfang to the south to deal with the Anhui clique and any attack that may have come from Sun's Kuomintang forces, while Wu himself prepared to face off again with Zhang's Fengtian army. Now called the "Jade Marshal" (玉帥) and generally acknowledged to be China's ablest strategist at the time, Wu Peifu was widely expected to win, and by doing so to finally put an end to various quasi-independent regional authorities.