An inquiry into the shooting of Jean Charles de Menezes has said prosecutors should consider charging three police officers with manslaughter.
Mr Menezes was shot seven times
Prosecutors have been asked to look at charging a Met commander and two firearms officers, the BBC has learned.
The Brazilian was shot by police at Stockwell station last July, after being mistaken for a suicide bomber.
The Crown Prosecution Service received the Independent Police Complaints Commission report in January.
It has been considering it since then and will announce what action is to be taken on Monday.
Both the Crown Prosecution Service (CPS) and the Independent Police Complaints Commission (IPCC) refused to comment.
Among the three who could face charges is Metropolitan Police Commander Cressida Dick, who was the senior designated officer in charge of the firearms operation on the day of the shooting.
The other two are the officers who shot Mr Menezes on 22 July, one day after the failed bomb attacks in London. They have not been named.
Recently retired Deputy Assistant Commissioner Alan Given - in charge of the firearms unit at the time of the shooting - told BBC Home Affairs correspondent Margaret Gilmore the two firearms officers should not be prosecuted.
Mr Given was not involved in the operation on the day Mr Menezes was shot, but he said he had spoken to the two firearms officers afterwards.
He said they thought they were protecting London from what could have been another terrorist attack.
"They felt that they had done exactly what had been required of them.
"They had gone into what they considered to be an enormously difficult situation; they'd acted in a very brave way. We're asking these people to do an enormously difficult, challenging thing.
"They thought, as a result of their actions, they had made London a safer place that day," he said.
The IPCC's report was a "damning indictment" of a catalogue of failures made on the day, added our correspondent.
Some who had seen the report said it painted a "devastating picture" of the police, from the moment surveillance officers began following Mr Menezes.
Criticisms aimed at the police are expected to include:
That a written log of events was changed afterwards by an officer, but not signed
That Met Police Commissioner Sir Ian Blair delayed the IPCC investigation. The watchdog said if it had gone in earlier it could have stopped the log being changed, although Scotland Yard denies this would have made a difference
That the firearms unit arrived so late to the incident, by which time Mr Menezes was underground. As police radios do not work on the Tube they then lost communications with base
Mr Menezes' family has called for charges to be brought against senior officers and those who pulled the trigger, saying they "cannot forgive".
Family spokesman Asad Rehman said there had been failures for which people had to take responsibility.
But our correspondent said the IPPC worked to a lower threshold and that many senior police officers and lawyers believed it was unlikely there would be enough evidence to bring prosecutions.
If no individuals face criminal charges, the CPS could decide to prosecute the force under health and safety laws.