Section 34. On and after July first in each year and before the regular appropriations have been made by the advisory board on county expenditures, the county commissioners and other officers authorized to incur liabilities payable by the county may incur liability for general maintenance and operation of regular county activities at a rate of expenditure which does not exceed in any month the sum spent for a similar purpose in any one month in the preceding year; provided, that said commissioners or officers may expend in any one month for any office or board created by law an amount not exceeding one twelfth of the estimated cost for said year for said office or board. Payments therefor may be made from any available funds in the county treasury, to be charged to the regular appropriation when made. No new or unusual expense shall be incurred, or permanent contract made, or salary increased, until an appropriation sufficient therefor has been made by the advisory board on county expenditures; except that salary increases in accordance with the salary schedule may be granted as set forth in section fifty-one B, and contracts made by a county for the exercise of its corporate powers or for any purpose as provided in sections fourteen and seventeen of chapter thirty-four may during any fiscal year, at the time of, or after, the making thereof, be extended without an appropriation, upon like or more favorable terms and conditions, for the whole or any part of the next fiscal year up to December thirty-first of that year or up to sixty days after passage of the budget of the next fiscal year, whichever date is later, provided that in no event shall the average monthly liability incurred with respect to the next fiscal year exceed the average monthly liability for such contract during the last six months of the then current fiscal year. Rentals and leases of real property may be entered into for a period not to exceed five years, provided that such limitation shall not apply to leases with the judicial branch of the commonwealth.

Notwithstanding the foregoing limitations upon the authority of the county commissioners and other officers to incur liabilities during said interval, such county commissioners and other officers may incur liabilities and make payments therefor from any available funds in the treasury to such extent as may be necessary for the purpose of contracting and paying for group insurance in accordance with the provisions of chapter thirty-two B.