(3)Notwithstanding anything contained in sub-rule (2),where the expenditure upon any original work on a national highway to the detailed estimate of the cost for which the [executing agency] [Substituted by Section O. 496(E), dated 20.8.1986 (w.e.f. 20.8.1986).] concerned has accorded technical approval and financial sanction, under sub-rule (2) of rule3, is likely at any time to exceed, or exceeds, the amount of such estimate and the revised estimate of the cost for the original work, including the excess is likely at any time to exceed, or exceeds, by more than fifteen per cent. of the original estimate but by not more than fifteen percent. of the rough estimate of the costs for the original work which the [executing agency] [Substituted by Section O. 496(E), dated 20.8.1986 (w.e.f. 20.8.1986).] had submitted to the Central Government and obtained the approval of that Government, technical approval and financial sanction to such revised estimate may be accorded by the [executing agency] [Substituted by Section O. 496(E), dated 20.8.1986 (w.e.f. 20.8.1986).] concerned subject to the conditions specified in the Schedule annexed to these rules:Provided that the amount of the revised estimate is not likely to exceed, or does not exceed [rupees fifty lakhs] [Substituted by Section O. 855(E), dated 5.11.1993, for " rupees twenty-five lakhs" (w.e.f. 5.11.1993).] :Provided further that the excess of expenditure is caused only by routine factors such as increase in the cost of labour or material and not due to revision in the scope or enlargement of the work or specifications already approved.
