Barack Obama's campaign for the White House is receiving increasing complaints about scam pollsters involved in dirty tricks operations to discredit the Democratic candidate.

Victims claim the fake pollsters work insinuations into their questions, designed to damage Obama. Those targeted in swing states such as Florida, Ohio and Pennsylvania include Jews, Christian evangelicals, Catholics and Latinos.

One of those to protest, Debbie Minden, who lives in a predominantly Jewish neighbourhood, Squirrel Hill, in Pittsburgh, Pennsylvania, told the Guardian that the pollster had begun by asking her the usual questions about her background and who she would vote for.

But the pollster went on to ask Minden, who is Jewish, how she would vote if she knew that Obama was supported by Hamas, the Palestinian militant group that runs Gaza and was responsible for most of the suicide bombings against Israel. "It is scare tactics. It is terribly underhand," she said.

The groups behind such polls have not been identified. One of the Republican groups working on behalf of John McCain's campaign, the Republican Jewish Coalition, acknowledges carrying out a survey about Jewish voters' views on Obama and Israel, but insists it was a legitimate exercise intended to test campaign messages on Jewish voters.

The RJC angrily dismissed comparisons between its exercise and a "push poll", the technique of using fake surveys to sway voters. Its poll was restricted to 750 people whereas push polls usually involve phoning thousands of people. It asked 82 questions, only 10% of which were devoted to Obama.

The technique of push polling is part of the election battle being fought on the ground in the swing states where the margins of victory have been narrow in past elections.

On a bigger scale, teams from each campaign are engaged in legal fights over who is entitled to vote, with Republican groups trying to have people in largely Democratic neighbourhoods disqualified.

Push polling was used with stunning effect in the 2000 Republican primary campaign in South Carolina where people claiming to be pollsters insinuated that McCain, then fighting George Bush for the party nomination, had illegitimately fathered a black child.

Bush went on to overturn McCain's double-digit poll lead in the primaries, and the origin of the calls was never fully established.

This year, the tactic surfaced again during the Republican primaries when calls were made highlighting the religion of one of the candidates, Mitt Romney - he is a Mormon, a religion viewed with suspicion by some on the Christian right.

An Obama campaign organiser in one of the swing states said there had been lots of complaints about push polling in his patch. Callers said questions frequently included a reference to the widespread belief that Obama is a Muslim, even though he has repeatedly said he is a Christian.

The organiser said another question was: would you be less likely to vote for Obama if Israel had to give up all of Jerusalem? "They make this shit up. They are good at it. The unassuming listener will not realise it is untrue," he said.

Minden, a school psychologist, received a call on a Sunday afternoon in the middle of last month. Living in a swing state, she was not surprised to be polled. "It sounded like a normal poll. Was I voting? Demographics? Age? Where we live? Then a question about which party I supported, who I preferred on the economy, on foreign policy, questions like that.

"They said; 'Are you Jewish?' and I said 'Yeh'. Then they said 'if you knew Barack Obama was supported by Hamas, would it change your vote? Would it change your vote if you knew his church had made antisemitic statements?'. All the hot button issues on Israel." She said she will vote for Obama as planned.

In Key West, Florida, another swing state, Joelna Marcus, 71, a retired professor, had a similar experience. She was asked if she would be influenced if she learned that Obama had donated money to the Palestine Liberation Organisation.

Marcus has since disconnected her telephone.

The Huffington Post website reported that a reader, named Rachel from Strongsville, Ohio, complained of a push poll that portrayed Obama as a radical leftwinger who had voted to let convicted child sex offenders out early and to allow them to live near schools.