The minimum is to have the right to present your own evidence, testify on your own behalf on the public record, and challenge your accusers. It's a challenge to retaliation.
Some of the most effective whistle-blower laws enfranchise whistle-blowers to go to court on the attack against the corruption or abuse of power through private attorney general statutes. It came out of England's Magna Carta initially. The False Claims Act in the United States, which allows the whistle-blowers to file lawsuits challenging fraud in government contracts, is America's most effective anti-corruption law. It has increased the take against fraud in government contracts from an average of around $10 million a year to an average of more than a billion dollars a year, and more than $3 billion a year in the last few years.