Gina Rinehart’s bitter family feud over a $5 billion dollar trust is due to be heard in an open court today nearly three years after it was first lodged.

Mrs Rinehart’s three eldest children – Bianca Rinehart, John Hancock and Hope Welker – lodged the case against her in September 2011, alleging she engaged in misconduct by changing the date they could access their money without telling them.

Ms Welker has since pulled out of the case after striking a deal with her mining billionaire mother.

Just before the Supreme Court civil trial was due to begin in late 2013, Mrs Rinehart made a shock announcement that she would step down as trustee.

The case being heard in Sydney may determine who will replace her.

The public feud has involved large legal teams and seen the release of private emails in which Mrs Rinehart has accused her children of being lazy.

She has spectacularly lost her fight to have it dealt with in mediation or private arbitration despite going to the Supreme Court, the Federal Court and to an appeals court.

As one lawyer quipped during one of the hearings: “It’s been to almost every court in the country.”

Bianca Rinehart expected in Sydney court

None of the family members has been in court for the three years the case has been running, but Bianca is expected to be the first witness today.

The trust, which was set up by Mrs Rinehart’s father Lang Hancock, owns about a quarter of Hancock Prospecting, Australia’s largest private company.

Mrs Rinehart has argued all along that she has contributed substantially to the trust and built it up.

Mrs Rinehart’s youngest daughter, Ginia, has sided with her mother all along in the matter.

After Ginia Rinehart’s appeal to have the feud dealt with in private arbitration was dismissed, the 25-year-old argued the civil trial would be a “farce”.

The case before Justice Paul Brereton is likely to run for four days.