Western diplomats have expressed deep concern at a decree from Afghan President Hamid Karzai granting him total control over a key election body.
The move gives him the power to appoint all five members of Afghanistan's Electoral Complaints Commission (ECC).
The watchdog helped expose massive fraud in last year's presidential poll, forcing Mr Karzai into a second vote.
The decree comes as Nato-led forces fight a major operation against the Taliban in central Helmand province.
The BBC has been told the outgoing UN representative to Afghanistan, Kai Eide, had struck a private deal that two of the five commission members would be foreigners.
'Devil in detail'
Under that agreement, one of the appointees was expected to have veto power.
But the deal does not feature in the new decree.
The commission - which previously had three foreign experts appointed by the United Nations - will play a vital role in this year's parliamentary poll.
The BBC's Chris Morris in Kabul says one Western official questioned if the international community would be willing to underwrite the costs of another election, which could be deeply flawed.
But another was less gloomy, telling our correspondent the decree was not necessarily a total disaster, and that the devil would be in the detail.
In a speech to parliament on the first day of its spring session on Saturday, President Karzai listed his priorities, which included reforming the ECC's structure.
He reportedly said that in preparation for this year's parliamentary elections, he would limit "interference from others" by "Afghanising" the poll process.
Mr Karzai was eventually declared the winner of last August's presidential election after a months-long fraud investigation which paralysed the country and delayed Nato members sending more troops to combat the insurgency.
The ECC's Canadian chairman and his two non-Afghan colleagues had led demands for the ballot-stuffing inquiry.
The former deputy UN envoy to Afghanistan said the lack of an international presence on the election commission would lead to a repeat of the fraud seen in the presidential poll.
"In principle, Afghanising the election process is a good idea," Peter Galbraith told the BBC.
"But... this clearly is not a matter of Afghanisation, it is a matter of getting rid of the international monitors who provided a degree of honesty in the election, so as to enable [Mr] Karzai and his allies to manipulate - steal, if you will - the upcoming parliamentary election."
Mr Galbraith was dismissed from his post last September after a row with his boss, Kai Eide, over how to handle the election crisis.
Nato TV apology
After the election watchdog discounted nearly one million votes for Mr Karzai, he agreed to a run-off.
But days before the vote in early November, it was scrapped, with officials citing a need to avert further political damage to Afghanistan and a rerun of the Taliban violence that marred the first round.
Mr Karzai's only rival, Abdullah Abdullah, had earlier pulled out of the run-off, saying that it would not be free or fair.
Dr Abdullah, who is currently in Paris, is expected to give his reaction to Mr Karzai's decree later on Tuesday.
There was more violence on Tuesday as at least seven people were killed by a bomb left on a bicycle near a bus station in the Helmand province capital of Lashkar Gah.
And as relatives of nearly 30 civilians killed in a mistaken Nato air strike on Sunday prepared to bury their dead, Nato commander Gen Stanley McChrystal went on Afghan television to say sorry.
More than 15,000 Nato and Afghan forces, meanwhile, were in the 10th day of Operation Moshtarak in the Helmand district of Marjah.
The mission aims to win public support by routing the Taliban, rushing in aid and strengthening the writ of local government. - BCC