N.J. Stat. § 40:41A-8
In any county in which a charter study commission has been established under this act, there shall also be established an advisory body to be known as the advisory board whose members shall have the right to participate in the deliberations of the charter study commission, but without the right to vote on commission recommendations or to endorse or dissent from any report of the commission by virtue of their official advisory role, although this in no way shall be deemed to inhibit their right to make comments as individuals after the release to the public of the charter study commission's report. The advisory board shall consist of the persons who, as of the second Tuesday of January next following the commission's organization meeting, shall hold the following offices: the director of the county board of freeholders, the county chairmen of the two political parties which received the largest vote in the county in three out of four of the most recent gubernatorial elections, the mayor of the municipality having the largest population in the county and the mayor of the municipality having the smallest population of over 250 in the county, according to the last population estimate published by the New Jersey Department of Labor and Industry, one Senator and one member of the General Assembly, both of whom shall be residents of the county at the time of their election to the advisory body. The Senator and member of the General Assembly shall be elected to the advisory body by a majority vote of the whole number of the county's board of chosen freeholders within 1 week of the approval of the charter study referendum by the county's voters.
Nothing in this act shall be deemed to prohibit the board of chosen freeholders from electing as legislative members of the advisory body any persons who are not at the time of their election to the advisory board incumbent legislators but who will be legislators as of 3 p.m. on the second Tuesday of January following the election of the charter study commission. If there is not at least one Senator and one member of the General Assembly residing in the county as of 7 days after the approval of the charter study referendum by the voters, the board of freeholders shall fill the seat or seats in question by electing one or two mayors of municipalities within the county to membership on the advisory board.
If the advisory board shall include among its members three or four mayors pursuant to the above provisions, no more than two of these mayors shall be of the same political party, unless there are no mayors of another party or without party affiliation in the county who will accept election to the advisory board. The mayor of any municipality operating under a nonpartisan form of government shall be deemed to be a member of the party in whose primary election he last voted. If he shall never have voted in a primary election, he shall be deemed to have no party affiliation.
The membership of the advisory board shall be promulgated by the chairman of the charter study commission not later than 3 p.m. on the second Tuesday of January following the commission's organization meeting. If for any reason any member of the advisory board shall vacate the office by virtue of which he sits on the board, his successor, regardless of such successor's party affiliation, shall also succeed him on the board on the effective date of his assuming his predecessor's office.
N.J.S. § 40:41A-8