A possible scenario is that there is no 'People's Budget' in 1909 and therefore no general election in 1910. Asquith calls a general election in 1912 in which the Conservatives win an overall majority. Balfour is still Conservative Party leader and he becomes Prime Minister. Carson is appointed to the cabinet. World War One starts as in OTL. Balfour, like Asquith, is not suited to be a wartime PM and Carson is the Tory Lloyd George equivalent who forces Balfour out and becomes Prime Minister in 1916.
As regards Ireland there would be no Home Rule Act but I don't have time to develop a possible Ireland scenario.