Parliament speaker Mohammad al-Lahham announced the poll, which is expected to return President Bashar al-Assad to office, for June 3 despite the ongoing conflict that has killed tens of thousands of people.
"Assad's plans for elections can only be designed to sustain his dictatorship," said Foreign Office minister Mark Simmonds.
"They will be conducted against the backdrop of non-stop regime attacks on civilians, hundreds of thousands living under regime siege in horrendous conditions, and in a climate of fear where thousands of non-violent opponents to Assad have been detained or have disappeared.
"Elections conducted on this basis fall far short of any international standard, and their outcome will have no value or credibility."
Simmonds urged Assad's regime to work to find a political solution to the three-year-old conflict.