States members have voted through the law that will reinstate senators in time for the next election.
The legislation enabling the return of the island-wide vote was passed by 28 votes to 17.
Politicians narrowly agreed back in March to bring back senators, reversing their 2021 abolition.
Every electoral district will lose a deputy, to make way for nine senators.
Town Constable Simon Crowcroft tried to get that number reduced to seven, with two extra St Helier deputies.
However, although he won the vote 24 - 21, he narrowly missed the 25 votes required for the idea to be adopted.
Another suggestion - for a separate election day for senators - was also defeated.
Deputy Montfort Tadier thought failed senatorial candidates should get the chance to run for deputy or constable.
That vote was lost 18 -28.
Deputy Hilary Jeune failed (20-22) in her attempt to require senatorial candidates to have a nominee from at least one person from each electoral district.
Jersey's politicians voted to adopt the Committee of Constables' idea to prevent a by-election being called if a senatorial seat becomes vacant close to a general election.
The timeframe will increase from six months to nine months.
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