In June, she celebrated her 70th birthday by performing on stage at the Sage Theatre, Gateshead, to a sellout audience.

At Easter, BBC4 marked the 40th anniversary of satirical TV comedy sketch series The Frost Report, during which Julie – who was a regular on the popular 1960s show – enjoyed a reunion with presenter David Frost and stars like John Cleese and Ronnie Corbett.

And last month she went back to the US for three special reasons – to meet up with family, to have a reunion with former school friends in Las Vegas, many of whom she had not seen for more than 50 years, and to vote for President-elect Barack Obama.

The success of Obama thrilled Julie, who wrote protest songs in the 1960s and despaired as a succession of British and US politicians – Thatcher, Reagan and George W Bush – put material and military might above spiritual and humanitarian concerns.

"I think some of the darkest years of our lifetime have been the Bush era, so destructive," she says.

"The success of Barack Obama has been a big light on my horizon. He is both black and white, I see him as an instrument of healing. I'm working on some songs about it and I talk about it on stage."

Her audience at Square Chapel, Halifax, on Thursday will hear some of her own songs, with a sprinkling of tracks by folk icons Bob Dylan and Buffy Sainte-Marie for good measure. And her new CD, which will be on sale on the night, will provide her fans with a thoughtful and thought-provoking Christmas present for a friend or relative.

"This tour is called Highway of Diamonds," she says. "The difference between now and the '60s is that I sing political songs but also self-awareness songs - about tuning in to our 'higher selves'. What I say is that before we can create peace in the outer world, we have to create inner peace.

"We are all on the 'Highway of Diamonds' that eventually leads to the stars, but we are so brain-washed that we forget.

"I sing a lot of songs from the '60s, especially songs with a message and songs of conscience, because I think they are still relevant today. I don't think I am indulging in nostalgia, it's about re-kindling our vision for our own lives."

The show will also have plenty of audience input. During the interval, Julie asks listeners for requests. "I don't know what I'm going to be singing so it's quite a good way for me to keep fresh," she says.

Julie, who is of Mexican and native American descent, came to Britain in 1964 from California. The following year, acting as humanitarian ambassador for Christian Aid, she visited Lebanon, Jordan and East Africa.

Returning to London to give her first solo concert, she became the first British-based folk singer to fill the Royal Albert Hall.

She has worked with numerous iconic musicians including John Paul Jones of Led Zeppelin and drummer Cozy Powell.

In 1968 she was given her own TV series of 17 shows – the first colour series produced by the BBC – which was sold to virtually every country in the world, including Russia. Her guests included Spike Milligan, Richard Harris, Leonard Cohen, Dusty Springfield, Donovan and Jimmy Page.

The following year she appeared at the Isle of Wight Festival where Bob Dylan made his comeback appearance after a five-year absence.

Back in the Swinging Sixties, she was compared in the US to singer Joan Baez, which annoyed her at the time. "We were both half-Mexican and both involved in politics, but I wanted to establish myself," she says.

And it also frustrated her that the track people seemed to associate her with most was the light-hearted Tom Paxton song for children, Goin' to the Zoo.

"Being 70 years old now, I take it in my stride," she says.

Julie, who lives in Hertfordshire, is looking forward to her trip to Calderdale. "I love the north and I have friends in Leeds, so I get to catch up with them," she says.

• Julie Felix is at Square Chapel, Halifax, on Thursday at 8pm. Tickets are £12 (£10 concessions) are available from the Square Chapel box office on 01422 349422.