Supporters of Green Party leader Jill have filed election challenges in more than 100 precincts in Pennsylvania. The campaign has also gone to court to extend the deadline from Monday in order make challenges in more districts.

“The Stein recount effort is mobilising concerned voters across Pennsylvania to request recounts in their precincts,” Ms Stein campaign manager David Cobb told Politico in a statement.

“Additionally, the campaign filed a legal petition in state court today on behalf of 100 Pennsylvania voters to protect their right to substantively contest the election in Pennsylvania beyond the recounts being filed by voters at the precinct level.”

Ms Clinton lost narrowly to Mr Trump in the three states Ms Stein is disputing (AP)

He added: “This petition will allow the campaign to pursue a full statewide recount in Pennsylvania if precinct-level recounts uncover any irregularities or tampering.”

The efforts in Pennsylvania follow the Green Party leader’s filing of ballot recount request in Wisconsin last Friday. The campaign intends to file a similar action in Michigan.

On Saturday, Ms Clinton’s campaign confirmed that it was supporting the effort to recount some votes in Michigan, Wisconsin and Pennsylvania.

Bernie Sanders says 'no one expects profound change' from recount

Writing on Medium, the Clinton campaign’s chief legal advisor, Marc Elias, said a decision had been taken to participate even though it had found no evidence itself of any hacking of the voting systems in any of the states, as some have suggested.

“Because we had not uncovered any actionable evidence of hacking or outside attempts to alter the voting technology, we had not planned to exercise this option ourselves, but now that a recount has been initiated in Wisconsin, we intend to participate in order to ensure the process proceeds in a manner that is fair to all sides,” he wrote.

In Pennsylvania, which has 20 Electoral College votes, Mr Trump won by roughly 68,000 votes, and in Wisconsin, which has ten such votes, his margin was even smaller: just 27,000. Michigan, which carries 14 votes, was called for Mr Trump on Monday, with the difference between the two candidates amounting to fewer than 12,000.