Britney Spears and her ex-husband Kevin Federline are due back in court on Tuesday for a progress review in the ongoing custody battle over their two children.

Federline was given full custody of Sean Preston, two, and Jayden James, one, after Spears staged a stand-off with police, emergency services officials and childcare experts when she refused to handover her sons following a scheduled visit in January.

The former couple has been battling the custody order ever since, but Federline recently relaxed his ex-wife's visitation rights, allowing her to spend extra time with her kids.

The pair will now appear at Los Angeles Family Court to re-evaluate the situation, and the hearing is expected to discuss the results of a psychiatrist's evaluation of Spears.

If Spears is deemed competent, Superior Court Commissioner Scott Gordon, who will preside over the hearing, could officially amend the agreement and allow the singer more official visits.