The Coalition’s dumped immigration spokeswoman, Sharman Stone, says she has been “done over by the Right” as Tony Abbott moves to harden the Coalition’s stance on immigration. The Australian understands the Opposition Leader will appoint Sydney MP Scott Morrison to the immigration porfolio in a new frontbench line-up expected to be announced today. Last night Dr Stone lashed out at her demotion, saying she had sought to steer a middle course between party moderates and hardliners.

Mr Abbott’s reshuffle comes as the number of unauthorised boat arrivals this year approaches 2500, following the interception of the 51st boatload this year on Sunday.

Mr Morrison was elected to parliament in 2007 following the retirement of Bruce Baird, an outspoken critic of John Howard’s hard line on immigration. His appointment to the front bench follows a widespread feeling within the party that Dr Stone had failed to “cut through” in her criticism of the government, a charge she angrily rejected.

“I’ve been done over by the Right,” Dr Stone told The Australian yesterday. “It’s about payback. Immigration was so difficult because you were sandwiched between the left and the right wing of the party. I happened to believe that I was steering the right path and I had a lot of support for that, including, of course, from the leader at the time.”

Dr Stone is one of a number of moderates understood to have been dumped from the shadow cabinet. One Turnbull supporter said yesterday the reshuffle had rewarded hardline Abbott supporters and punished Turnbull backers. Dr Stone’s public outburst came on the same day deposed leader Malcolm Turnbull attacked in his blog Mr Abbott’s stance on climate change, suggesting the Coalition’s internal bickering was far from over.

Nevertheless, Dr Stone, who has accepted a position as the Coalition’s spokeswoman for women, youth and early childhood, pledged to work with her successor, as well as Mr Abbott, her ideological opposite. She said she would bring considerable experience to her new role. “I’m well known for championing the rights of women, particularly in the area of reproductive health and also indigenous, rural and migrant women,” she said.

Dr Stone fired a warning shot over the new Opposition Leader’s bow, saying it was essential the Coalition did not fall back on the hardline policies of the past. “It will be essential that the moderates that remain in the party continue to steer through the middle ground, ensuring that the real grassroots of the party continues to build in multicultural communities,” Dr Stone said. “After all, we were the party that abolished the White Australia policy with Harold Holt in 1966.”

Dr Stone’s remarks came as authorities on Christmas Island prepared to process a boatload of 40 people intercepted on Sunday night — the 51st boat to arrive this year. All told, the boats have ferried 2353 passengers and 115 crew to Australia’s shores, bringing to 2468 the number of unauthorised arrivals by boat this year. More than half of those people, 1286, remain in immigration detention on Christmas Island.

Refugee Council of Australia chief executive Paul Power criticised the system of offshore processing, saying it made more sense to manage asylum-seekers on the mainland. “Years of strident political debate has lead to a situation where decisions are made to minimise political embarrassment to a government,” Mr Power said. “Both major parties have done that.”