But five months down the line since its election, Belgium still does not have a government and a quick solution remains unlikely.

While the negotiating parties have succeeded in concluding several partial agreements – on justice and immigration for example – an overall agreement still hangs in the balance.

Legal experts now fear that if Belgium fails to have a new government by 13 December, the outgoing government, normally only charged with 'current affairs', will not have the powers to sign the document.

"The concept of "current affairs" concerns a category of non-written legal rules, constitutional habits; and it is accepted that in general it covers three situations," legal experts Carine Doutrelepont and Pascal Lefèvre wrote in Belgian daily Le Soir.

These three situations are the day-by-day decisions of average or little importance, more important decisions that are the result of commitments made earlier, and urgent matters which need to be regulated immediately to avoid serious damage to the common good.

According to the experts, putting a signature to the Lisbon treaty is unlikely to fall in any of these three categories, although it could be argued that a signature only implies finishing a process begun much earlier.

"It would not be the first time that the conclusion of an international treaty is deferred," the experts warned.

It was agreed by member states that the treaty would be ratified at the latest by 1 January 2009, but any delay of the signing moment could mean that the treaty would come into force later than planned.

On Monday (5 November), Belgium matched its previous record for government-forming negotiations. The longest period was 148 days in 1988.

Flemish parties are demanding more power for the regions, a course of action that is vehemently opposed by the French-speaking parties, who fear a gradual break-up of the country.