Spain is trying to cut its deficit from 5 percent in 2015, when it widely overshot a 4.2 percent target agreed with the European Commission.
It may be granted one or two extra years to get under a 3 percent recommended threshold, however, amid warnings that Spain's social security system is way off its revenue targets.
The European Commission is also due to decide on Wednesday whether or not to fine Spain in relation to its missed deficit goal in 2015.