Given the following context:  Despite the public acclaim that had greeted Shackleton's achievements after the Nimrod Expedition in 1907–1909, the explorer was unsettled, becoming—in the words of British skiing pioneer Sir Harry Brittain—"a bit of a floating gent". By 1912, his future Antarctic plans depended on the results of Scott's Terra Nova Expedition, which had left Cardiff in July 1910, and on the concurrent Norwegian expedition led by Roald Amundsen. The news of Amundsen's conquest of the South Pole reached Shackleton on 11 March 1912, to which he responded: "The discovery of the South Pole will not be the end of Antarctic exploration". The next work, he said, would be "a transcontinental journey from sea to sea, crossing the pole". He was aware that others were in the field pursuing this objective. On 11 December 1911, a German expedition under Wilhelm Filchner had sailed from South Georgia, intending to penetrate deep into the Weddell Sea and establishing a base from which he would cross the continent to the Ross Sea. In late 1912 Filchner returned to South Georgia, having failed to land and set up his base. However, his reports of possible landing sites in Vahsel Bay, at around 78° latitude, were noted by Shackleton, and incorporated into his developing expedition plans.News of the deaths of Captain Scott and his companions on their return from the South Pole reached London in February 1913. Against this gloomy background Shackleton initiated preparations for his proposed journey. He solicited financial and practical support from, among others, Tryggve Gran of Scott's expedition, and the former Prime Minister Lord Rosebery, but received no help from either. Gran was evasive, and Rosebery blunt: "I have never been able to care one farthing about the Poles".Shackleton got support, however, from William Speirs Bruce, leader of the Scottish National Antarctic Expedition of 1902–1904, who had harboured plans for an Antarctic crossing since 1908, but had abandoned the project for lack of funds. Bruce generously allowed Shackleton to...  answer the following question:  What is the last name of the former prime minister who did not provide financial support for the leader of the Nimrod Expedition?
The answer to this question is:
Rosebery