The President of Uganda on signing into law a bill harshening penalties for those arrested for being gay, made ludicrous claims that gay people give each other worms through sex, and that people are only gay because they have sex for money.

President Museveni signed the bill in front of politicians and reporters on Monday at 1.54pm (10.54am GMT) at State House, his official residence in Entebbe.

The law calls for first-time offenders to be sentenced to 14 years in prison and makes it a criminal offence not to report someone for being gay.

Lesbians are covered by the bill for the first time.

On signing the bill, the president questioned why gay men “failed” to be attracted to women, described them as “mercenaries” who have sex for money, expressed displeasure at the idea of oral sex and claimed that he had “listened to scientists” as a basis for his claims.

Going on, he also said that there was something “really wrong” with gay people, and that he is “prepared” to be on a collision course with the west over the law.

He said: “I have failed to understand that you can fail to be attracted to all these beautiful women and be attracted to a man.”

“That is a really serious matter. There is something really wrong with you,” he said.

“Homosexuals are actually mercenaries. They are heterosexual people but because of money they say they are homosexuals. These are prostitutes because of money,” he said, asserting that he had taken the time to get scientific advice before signing off on the law.

“No study has shown you can be homosexual by nature. That man can choose to love a man… is a matter of choice. After listening to the scientists, I got the facts. Can somebody be homosexual simply by nature? The answer is no.”

Describing oral sex as a “culture”, and the mouth as an “address”, he went on to say that it was “engineered for kissing”, and that the mouth was not meant for oral sex.

He said: “One of the cultures that we detest is oral sex. The mouth is for picking food, not for sex. We know the address for sex. That address is not for sex,” he said. “The mouth is for eating not for sex. The mouth is engineered for kissing.

“It is not healthy. You can contract STDs. You push the mouth there, you can come back with worms and they enter your stomach because that is a wrong address. You can also contract Hepatitis B.”

Blaming the West for the presence of gay people in Uganda, he said “arrogant and careless Western groups” had been “coming in our schools and recruiting homosexuals into homosexuality and lesbianism”.

“Initially I have not paid attention to it because I was busy with the immediate issues of defence, security, electricity, the roads.”

“When finally, when I concentrated my mind on it, I distilled three problems: number one, those who are promoting homosexuality and recruiting normal people to it. Secondly, as a consequence of number one, many of those recruited, are doing so for mercenary reasons. To get money. In effect, homosexual prostitutes. These mercenary homosexual prostitutes have to be punished. Just like those who are recruiting them.”

“Number three, homosexuals exhibiting themselves. Exhibition of homosexuals, advertising yourself that you are homosexual.”

Concluding, he addressed criticism from the West for the law. Critics include Deputy Prime Minister Nick Clegg, Foreign Secretary William Hague, EU foreign policy chief Baroness Ashton and US President Barack Obama.

“I advise friends from the West not to make this an issue because if they make it an issue the more they will lose,” he said. “This is social imperialism. To impose social values of one group on our society.

“I would advise Western countries, this is a no-go area… I don’t mind being in a collision course with the West. I am prepared.”