The former Oscar-winning actress approached startled holidaymakers on their sun-beds in temperatures soaring into the Eighties to hand out sticks of rock with "Tory lies" through the middle.
Labour's special campaign whirly hats were in more demand in Benidorm than last week in Cleethorpes when John Prescott took Labour's "summer offensive" to the beaches there.
The Spanish resort is famous for its sun, fun and sangria, but there appeared to be at least some, limited, interest in socialism.
One topless sunbather, Helen Fayle, 20, from Co Durham, said: "It's so mad, it's brilliant. It's a really original idea."
Ms Jackson posed for the photographers between two burly engineers from Stockport. Alan Turner, 35, with the word "Tracey" tattooed all over one shoulder, said: "Where's Susannah York and Reedy?"
But the star of Women in Love had moved on to more sunbathers to remind them that the Tory lie-machine would be working at home after their holiday.
In one of the strangest press conferences Labour has staged, Ms Jackson, with the Mediterranean lapping over her sensible shoes, said: "I have only met smiles. If I was here day after day, I would think that the reaction would change, but that is not the point. This is to highlight the same old Tory lies at home and what Labour stands for."
She unveiled a poster in Alicante on the main road to the Spanish resorts, along which travel some of the 4 million British tourists who come each summer. Arriving for their holidays, they will see Labour's message: "No wonder you need a break ... same old Tories, same old lies."
Ms Jackson, shadow transport minister, was also keeping within Labour's campaign budget. She travelled in economy-class seats with the other trippers.
As a film star, Ms Jackson, who won a second Oscar for A Touch of Class, had a reputation of being a dream to work with. In spite of the sticky temperatures, she proved a trouper for Mr Blair's campaign team yesterday, obliging the cameras by walking around the beach when they wanted to get a topless bather in focus. "I am not a great holiday person," she said. Ms Jackson prefers spending her holiday in her garden in south London but plans to travel Eurostar to Paris for a break.
The serious message behind yesterday was that Labour will not allow any let-up, even during the traditional ceasefire of the holiday period, against what it believes is the most offensive campaign ever waged by the Tories - the "Demon Blair" advertisements.
Before flying back to London, Ms Jackson said that she believed the Tory campaign would backfire on Brian Mawhinney, the chairman of the Conservative Party. But the sunbathers in Benidorm can rest easy now. The Tories have decided to leave the beaches alone.Reuse content