Clive Lewis has resigned from his role as Shadow Business and Energy Secretary.
It comes after he defied party orders to back the Brexit bill and start the process of leaving the EU.
Mr Lewis, who held the post since October last year, was one of 52 Labour MPs to do so, following which he resigned from the front bench.
The draft legislation was approved by 494 votes to 122 and now moves to the House of Lords.
He said: “When I became the MP for Norwich South, I promised my constituents I would be Norwich’s voice in Westminster, not Westminster’s voice in Norwich.
“I cannot, in all good conscience, vote for something I believe will ultimately harm the city I have the honour to represent, love and call home.”
Labour Leader Jeremy Corbyn said he “understands the difficulties MPs representing constituencies which voted Remain have in relation to the European Union Withdrawal Bill”, adding: “MPs have a duty to represent their constituents as well as their party.”