Friday, August 20, 1999 Published at 09:15 GMT 10:15 UK
Protesters crowd streets in Philippines
A similar demonstration was held in Quezon City
Tens of thousands of people have protested against changes to democracy in the Philippines proposed by President Joseph Estrada.
Police said about 25,000 people joined the demonstration, with thousands more watching from high-rise office blocks.
Mrs Aquino and Cardinal Sin told the crowd that proposed changes to the constitution do not need to be implemented.
Mr Estrada has asked Congress to amend the constitution to remove provisions which, he says, deter foreign investors, such as a ban on foreign ownership of land.
Cardinal Sin said constitutional changes were not needed to foster economic growth, blaming economic problems on what he called the "corruption" of Mr Estrada's government.
"Constitutional constraints are not the cause of our economic problems," he told the crowd.
"It is caused by corruption in government. Businessmen's money is going to waste due to bribery."
He criticised Mr Estrada for going back on his inaugural pledge to protect the constitution, and said he would use the church's influence to block the plans.
"We will not allow anyone to trifle with our democracy," he said.
Mrs Aquino and Cardinal Sin headed the People Power Revolution that overthrew the regime of President Marcos in 1986.
The rally's organisers believe that some of the abuses committed by the Marcos regime are in danger of reappearing under President Estrada, says the BBC's John McLean in Manila.
The Makati demonstration was a deliberate revival of the People Power phenomenon that deposed President Marcos.
Mrs Aquino is particularly concerned at the increasing influence of the family and associates of Mr Marcos.
She told the rally: "The issue is trust, not in the president but in the company he keeps."
Mrs Aquino and her followers believe that there has been a return to economic cronyism, that the freedom of the press is under attack and that the president's plans to amend the constitution have a nefarious purpose.
Mr Estrada denies all the accusations. He is intending to show that he retains the immense popularity that won him last year's presidential election.