Section 51 of the Central Provinces Local Self-Government Act, 1920, empowered a district council, subject to the previous sanction of the local Government, to impose "any tax, toll or rate, other than those specified in ss. 24, 48,49, and 50.'' On March 12, 1935, an Independent Mining Local Board functioning in the area in which the petitioners were working certain mines situated therein, and having vested in it all the powers of a dis- trict council, resolved to impose a tax on coal, coal-dust and coke manufactured at the mines or sold within the territorial jurisdiction of the Board. The petitioners who were served with notices of demand requiring them to pay certain sums of money as the tax due by them for despatches of coal from their mines, challenged the legality of the levy of the tax on the grounds, intl'f alia (1) that the Act which by s. 51 authorised the imposition of the tax, had been passed by the local legislature without the previous sanction of the Governor-General, thereby contra- vening s. 80A(3) of the Government of India Act, 1915, and that even if it was found that the Act was validly passed before the coming into force of the Government of India Act, 1919, which introduced s. 8oA into the Act of 1915, the power conferred by s. 51 to levy tax was exercised only in 1935 and by that date s. 8oA had been introduced into the Government of India Act, 1915, and that thereafter there could be no legal imposition of a tax without the previous sanction of the Governor-General being obtained, (2) that s. 51 of the Central Provinces Local SelfGovernment Act, 1920, on its language and ,in the context of other provisions referred to in that section, did not authorise ~ the levy of a tax of the nature of the coal tax, and (3) that, in any case, the tax ceased to be legally leviable after the coming