Any powers or duties or executive functions which may be exercised or performed by or on behalf of the municipal council may be delegated, in accordance with rules to be made by the Government in this behalf, to the president or to the vice-president, or to the chairman of any committee, or to one or more stipendiary or honorary officers, but without prejudice to any powers that may have been conferred on a Municipal Commissioner or Chief Officer under Chapter XIV or any committee by or under section 63; and each person, who exercises any power or performs any duty or function so delegated, may be paid all expenses necessarily incurred by him therein:

Provided that in a municipality for which there is a Municipal Commissioner the power or duties or executive functions under this Act or under any rule or bye-law made there under conferred or imposed upon or vested in the Municipal Commissioner shall not be delegated save as provided in section 344.