At issue is a clause in the final communique produced by international talks in Vienna last week that included 17 countries -- among them key regime backers Russia and Iran.
It stipulates that future elections following a transition process must be held "under UN supervision" and "with all Syrians, including the diaspora, eligible to participate".
"Countries hostile to Syria prevented Syrians from voting in their embassies during the 2014 (presidential) elections," said Wadah Abed Rabbo, editor-in-chief of Syria's Al-Watan newspaper, which is close to the regime.
"Today we see them relentlessly demanding the vote for Syrian refugees or those living abroad, which raises questions about the intentions of these countries."
His newspaper on Sunday ripped into the communique produced by the unprecedented talks to try to end more than four years of a war that has killed upwards of 250,000 people.
"The Vienna process seems modelled on the positions of Damascus and Moscow, because several provisions affirm the right and the freedom of Syrians to determine their fate without external interference," the daily said.
"But the communique also includes a lot of external interference.
- 'Regime would be beaten' -
"Such interference does not stop at the choice of opposition figures (to participate in a transitional government) but extends to authorising Syrian refugees to take part in the political process, even though they are subject to all kinds of material, moral and even administrative blackmail."
The daily accused the "enemies of Syria" of planning to exploit diaspora voters "to win votes and interfere indirectly in the shaping of the country's future".
Backers of Syria's opposition have long insisted that President Bashar al-Assad cannot play a role in the country's future.
US diplomats see including the diaspora voting clause in the electoral section of the communique as a victory for their campaign to sideline the embattled leader.
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Experts say free and fair elections that include the Syrian diaspora would almost certainly see the regime ousted.
"If real elections were held, including the diaspora, the regime would be beaten by a candidate from or supported by the Muslim Brotherhood, who are the only ones able to mobilise the Sunnis in the diaspora," said Fabrice Balanche, a Syria expert at the Washington Institute for Near East Policy.
"With Qatar's money and support from Turkey, they could get the refugee vote," he added.
"I doubt therefore that the regime, the Russians, and the Iranians will accept this electoral process."
Syria last held elections in June 2014, with Assad re-elected for a seven-year term with 88.7 percent of the vote.
- 'Voting in embassies only' -
However, polling took place only in government-controlled territory and in several dozen countries that have not cut their diplomatic ties with Syria's government, including Lebanon.
Despite a diaspora that includes four million refugees in addition to migrants who left before the war, just 200,000 people voted overseas, according to a Syrian official.
The election was dismissed as a "farce" by the opposition and its international backers.
The key opposition Syrian National Coalition has already dismissed the possibility of holding new votes under similar circumstances, although a member welcomed the stipulations of the Vienna statement.
"The participation of Syrians abroad in a presidential election that comes at the end of the transitional phase and after a new electoral law would be a positive step," Coalition member Hisham Marwa told AFP.
In Damascus, however, analyst Bassam Abu Abdallah, who is close to the government, said the constitution would prevent anti-regime players from influencing a vote taking place in the diaspora.
"Voting can only be held in Syrian embassies, according to the constitution, not in camps or any other place that does not fall under the framework of Syrian sovereignty," said Abu Abdullah, director of the Damascus Centre for Strategic Studies.
"Any election taking place otherwise violates the logic of the constitution," he added.
"In addition, voters are required to have official papers, to have no links to terrorists and cannot be criminals or have been sentenced for crimes."sk/sah/srm