Petition for annexation - appointment of commission.

If there is presented to the legislative authority of a municipal corporation proposed to be annexed to an adjoining or contiguous municipal corporation, a petition signed by resident electors, who voted at the last regular municipal election, numbering not less than twenty-five per cent of the number of electors who voted in such election in the territory proposed to be annexed, representing their desire that such legislative authority take the necessary steps to select and appoint three commissioners to represent such municipal corporation in annexation proceedings, and if such petition is accompanied by a certificate verified on belief by oath, from the clerk of the board of elections of the county in which the municipal corporation is located, to the effect that the petition does contain the names of resident electors who voted at the last regular municipal election, of a number not less than twenty-five per cent of those who voted at such election, the legislative authority shall, within thirty days after the presentation of such petition, pass an ordinance declaring its intention to enter into negotiations with the municipal corporation with which annexation is proposed and shall appoint the three commissioners to represent it in such negotiations.