The Democratic Party in Maine picked its new candidate for a key US Senate race on Saturday, after the original nominee was pressured to drop out over sexual misconduct allegations.

Delegates to a hastily organised nominating convention picked Troy Jackson, a former state senate president, to go up against Republican incumbent Susan Collins.

“Thank you, Maine. In 101 days, we will defeat Susan Collins and reclaim our Senate seat. Let’s get to work,” Jackson said on social media.

The move comes just over two weeks after the prior candidate, Graham Platner, dropped out.

A Marine veteran, oyster fisherman and political newcomer, Platner had earlier won the Democratic primary with an energetic, anti-establishment message that gained him national prominence.

He weathered earlier scandals, including one related to a Nazi-linked tattoo, but his support plummeted after a former partner publicly accused him of rape.