First National Bank's apology to the ANC sends a message to companies that it is not acceptable to question or criticise the ruling party, the DA said on Friday night.
"In doing so [apologising] it has shown that it is acceptable to be bullied by the governing party, and it has shown the ANC that its bullying tactics work in suppressing critical voices," Democratic Alliance spokesman Mmusi Maimane said in a statement.
"Dissenting voices are healthy in a democracy, and the ANC's overblown offense at FNB's advert was inappropriate and petty. But the ease with which FNB is willing to grovel before the ANC and abandon its principled position is equally inappropriate and bad for democracy."
He said it was little surprise that many South Africans were already considering closing their FNB accounts.
Earlier, the African National Congress said FNB apologised for its "You Can Help" campaign, which features a number of videos of children in school uniform reading their hopes for the country.
Business Report published quotes from some of the videos.
"The country is being overrun by poverty... while [President] Jacob Zuma is renovating his home," said a youth from KwaZulu-Natal.
A Gauteng university student said: "The government is only thinking for themselves... I'm from a rural area and the government doesn't see what's happening."
A KwaZulu-Natal high school pupil said: "... Politicians tend to be the most destructive and eruptive (sic) aspect of our country... We need motives and a clear vision... We must not depend on our leaders. Each person must become their own hero."
In a statement, the ANC said it met with FNB and pointed out that the video clips were a deliberate attack on the party and that it had a negative impact on business confidence and could undermine the promotion of investment into the country.