Prime Minister John Key today paid tribute to one of the most respected and admired leaders of Waikato-Tainui, Raiha, Lady Mahuta.

In the House today the Prime Minister extended his sympathy to the whanau, friends and colleagues of Lady Raiha.

Mr Key, and a number of his ministerial colleagues, will travel to the Waikato tomorrow to pay their respects to Lady Raiha.

"Lady Raiha was best known to many of us for her Waikato-Tainui links, but she always acknowledged her northern tribal connections, too," says Mr Key.

"Following the death of her husband, Sir Robert, in 2001, Lady Raiha took on a leading role in Waikato-Tainui affairs, focusing particularly on the Waikato River claim.

"Lady Raiha was passionate about her cause. She was determined to complete the task left to her by her late husband. In doing so, she was respectful of other views but forthright with her own: she was open and honest during the process."

Mr Key says he had spent time with Lady Raiha just last Friday, and was struck by how she maintained her dignity and commitment to the Waikato-Tainui cause despite her illness.

"Lady Raiha will be greatly missed by the people of Tainui and particularly by her children: Tukaroto; our Parliamentary colleague, Nanaia; and Tipa.

Lady Raiha was 67 years old.