The former lover of Finland’s Prime Minister was today cleared by a court of any wrongdoing for publishing a steamy kiss-and-tell memoir which revealed how he wooed her with baked potatoes and dumped her by text message.

Susan Ruusunen was sued by Matti Vanhanen for disclosing intimate details of their affair in the run-up to last year’s general election -- which he won after her book coincided with a last-minute rise in his poll ratings.

Vanhanen objected to the Finnish public learning about his routine of a sauna before sex and spuds afterwards but the jury in Helsinki narrowly rejected 52-year-old's claim for damages for invasion of his privacy.

The book, "The Prime Minister’s Bride," claimed that Vanhanen did not meet Ruusunen, 36, in IKEA when helping her carry furniture, as he himself had claimed. Instead, they met on a dating website when the prime minister answered Ruusunen’s ad.

“My stomach is all butterflies,” he wrote in a text message the day before they met for the first time, she said.

The two lovebirds had many secret rendezvous, and Ruusunen’s book detailed the PM’s romantic side.

“He kisses so passionately that the car windows were steamed up,” she wrote.

The book claimed that clandestine visits by the brunette soon became the highlights of the prime minister’s week following his divorce in 2005.

When she visited, he always wanted to take a sauna before making love and afterwards usually served her dinner, she said.

After having sex, the prime minister usually wanted beef and potatoes, she wrote. He especially liked them baked.

“Once, when he kissed me, he said that I tasted better than oven-baked potato,” Miss Ruusunen wrote. “That was great.”

Ruusunen confessed in the memoir that she tempted the prime minister to have wild sex on the furniture in various rooms. “Unfortunately sex on the kitchen table never happened,” she wrote.

In the summer of 2006 they were seen together in public for the first time but just a few weeks later Vanhanen ended the nine-month relationship.

Ruusunen claimed that the prime minister did not end the relationship in a gentlemanly manner but used the same method as Scandinavian high school students. He simply sent her a short text message saying, “It’s over.”

Ruusunen, who last year changed her surname from Kuronen to the Finnish word for Cinderella gave several interviews and quickly became a media darling. Many more journalists covered her press conference on the controversial book release than the number covering her ex-lover’s press conferences in the Helsinki government offices.

Vanhanen, who has represented Finland’s Center Party in parliament since 1991 and was elected prime minister 2003, reported the book to the police on the eve of the 2007 election.

He brought his case only against the publisher, Kari Ojala, demanding 1,000 euros in compensation. But the state prosecutor joined the case and demanded a prison sentence for Ojala for breach of privacy and damages of 50,000 euros, as well as 7,000 euros from Ruusunen.

The court verdict was close, with two jurors voting to acquit Ruusunen and two voting for conviction. In an evenly divided jury the mildest alternative prevails, according to Finnish law, even through the chief judge also voted for a conviction.

“Finland still is a state governed by law,” the publisher Ojala said afterwards.

Vanhanen was reported to be very upset with the verdict. Earlier, he said: “I believe a leading politician must be allowed to have a private sphere which is not open for the public.”

The nation’s feelings are likely to be evenly divided. A poll showed that 42 per cent of Finns sided with the PM and 39 per cent with Ruusunen.

If it was intended to bring an end to the controversy, the case seems to have had the opposite effect.

The 160-page book seems destined to become the book of the year in Finland and to sell in record numbers.