Section 33. (a) The owners may amend the project instrument or any unrecorded document governing the project, or approve or disapprove any proposed expenditure, in the manner provided by this section in addition to any manner permitted by law or by the instrument or document.

(b) Any owner may deliver to the managing entity a petition containing the language of any proposed amendment or proposal for the approval or disapproval of any proposed expenditure and signed by owners of at least one time-share or other estate or interest in each of a number of units to which at least ten per cent of the votes are allocated, or any smaller percentage specified by the document to be amended. The owner delivering said petition may attach to it a letter of not more than two pages to be mailed with the ballots. Within ten days after receiving said petition, the managing entity shall mail to each owner a ballot setting forth the language of the petition and affording an opportunity to indicate a preference between approval and disapproval of said proposed amendment or proposal, together with a copy of any letter of not more than two pages attached by the owner who delivered said petition. The ballot may also be accompanied by a letter of not more than two pages from the managing entity recommending approval or disapproval of said proposed amendment or proposal.

(c) On the date specified pursuant to clause (2) of subsection (c) of section thirty-two, the managing entity shall examine the ballots that have been returned and calculate the vote accordingly. A signature on the petition shall be treated for the purpose of subsection (f) of section thirty-two as a ballot from the signer indicating approval of the proposed amendment or proposal. A simple majority of the votes counted shall be sufficient for the adoption of the proposed amendment or proposal unless the law or the document to be amended specifies a larger majority or, in the case of a proposed expenditure, the project instruments specify a larger majority not exceeding sixty-six and two-thirds per cent. No document may specify more than a simple majority for any proposed amendment or proposal the managing entity could have effected unilaterally. No proposed amendment or proposal may be adopted by an initiative unless the ballots favoring the proposed amendment or proposal represent at least twenty-five per cent of the votes allocated to all owners.

(d) A proposed amendment or proposal adopted pursuant to this section may not be repealed or modified within two years except by another initiative pursuant to this section. After said two year period, the managing entity may not repeal or modify the result without the approval of the owners in a referendum. If the project instrument permits the managing entity to initiate a referendum for said purpose, no referendum may be initiated for said purpose more often than once every two years.