The country that hosts the centre of the global diamond trade wants sanctions on the state-run Zimbabwe Mining Development Corporation (ZMDC) removed, putting it at odds with other EU countries, such as Britain, which is reluctant to rush into a move that could be seen as rewarding Mugabe.
EU states are squabbling over how to interpret an agreement by EU foreign ministers in February to lift sanctions on ZMDC within a month of the July poll unless EU governments unanimously agreed the vote was not "peaceful, transparent and credible".
The deal was part of an EU strategy of easing sanctions to try to encourage 89-year-old Mugabe, Africa's oldest leader who has ruled the former British colony for 33 years, to hold a fair election.
Mugabe overwhelmingly won the July 31 vote but it was denounced as a "huge fraud" by his main rival Morgan Tsvangirai.
The EU has expressed "serious concerns" over the alleged irregularities.
However, Belgium - home to the world's leading diamond trading hub at Antwerp - argues the EU has not refused to recognise the election and so the February agreement must be respected and sanctions on ZMDC lifted.
A spokesman for the Belgian Foreign Ministry said an agreement was confirmed by EU member states last Friday and it was a question of drawing up an instrument lifting the sanctions on ZMDC, something expected to happen soon.
This interpretation of the debate is not shared by EU officials who say talks are on-going.