Pope Francis omitted a short but powerful section of his speech to Congress – in which he warned politicians not to be a “slave” to the economy or finance – because he lost his place and accidentally skipped part of his script, the Vatican has said.

The remarks could have made the assembled crowd of lawmakers a little uncomfortable, given the widely held perception that members of Congress from both parties are too beholden to special interests.

Lawmakers raise tens of millions of dollars from companies and other interests – especially banks – to help fund their campaigns. Companies also pay lobbyists tens of millions of dollars every year to help sway, mould, and kill proposed legislation to suit their needs.

In his speech, the pope said: “It is important that today, as in the past, the voice of faith continues to be heard, for it is a voice of fraternity and love, which tries to bring out the best in each person and in each society. Such cooperation is a powerful resource in the battle to eliminate new global forms of slavery, born of grave injustices which can be overcome only through new policies and new forms of social consensus.”

But – the only deviation from a copy of the speech shared with reporters by the Vatican – the next lines were omitted.

According to the written text, Francis was going to read the “all men are created equal” clause of the Declaration of Independence. Then, he was supposed to say: “If politics must truly be at the service of the human person, it follows that it cannot be a slave to the economy and finance.”

Asked about the gap, Federico Lombardi, the Vatican spokesman said the slip was unintentional. According to Lombardi, Francis lost his place in the speech and accidentally skipped four lines.

Fr Lombardi, papal spox, says #PopeFrancis lost his place for min, accidentally skipping 4 lines in speech to Congress. Full text = valid. — Cindy Wooden (@Cindy_Wooden) September 24, 2015

Although Francis did not speak those lines, he is known as a critic of corruption, and sometimes spoke out against corruption in politics in his native Argentina. In March, while on a tour of southern Italy, he condemned the “stink of a corrupt society” that corrodes hope and marginalises immigrants.