The B.C. pair accused of masterminding the so-called honour killing of Jaswinder (Jassi) Sidhu have lost a last-ditch attempt to avoid extradition to India.

Malkit Sidhu and Surjit Badesha — Jassi Sidhu's mother and uncle — had applied for a stay of extradition proceedings because they claimed there was an abuse of process in a plan to whisk them out of Canada last year.

Malkit Sidhu and Badesha are accused of planning Jassi Sidhu's murder because she ignored the family's wishes and married a poor rickshaw driver.

Jassi Sidhu, 25, had her throat slit and body dumped in a canal after she and her new husband were attacked by a group of armed men during a trip to India in 2000.

Jassi's mother, Malkit Kaur Sidhu, and uncle, Surjit Singh Badesha, pictured in a sketch from a previous court appearance. (CBC)

Her mother and uncle were ordered deported to India to face charges of conspiracy to commit murder in 2017, but their extradition was brought to an abrupt halt as they were boarding the plane to Delhi, when their lawyers filed a last-minute application to keep them in the country.

Their lawyers asked for a review of the Justice Minister Jody Wilson-Raybould's decision to surrender the pair. Lawyer Michael Klein said Wilson-Raybould hadn't considered new evidence on prison conditions in India.

Klein sought a stay of proceedings, but the B.C. Court of Appeal rejected the application on Tuesday.

Jaswinder (Jassi) Sidhu, right, had her throat slit and body dumped in a canal. (CBC)

A three-justice panel found there had been an abuse of process when Malkit Sidhu and Badesha were taken from their B.C. jails and flown to Toronto for extradition because they weren't given the opportunity to consult their lawyers.

The panel found Wilson-Raybould's conduct amounted to an abuse of process, but that her actions did not warrant a stay of proceedings given the gravity of the accusations.

"This is a close case but we conclude the balance favours denying the stay," the decision reads, noting Malkit Sidhu and Badesha are "charged with the most serious crimes."

"It was reasonable for the minister to conclude that it was in the interests of justice to surrender the applicants."

Jaswinder Sidhu and her husband, Sukhwinder Mithu Sidhu, were attacked in Punjab in June 2000. Jassi was kidnapped and murdered. Her husband was badly beaten but survived. (CBC)

Malkit Sidhu and Badesha aren't out of legal options. Klein said they have 30 days to file a leave application to appeal with the Supreme Court of Canada.

The lawyer would not confirm if they plan to make that application. Klein said his clients remain in Canada, but would not say where.