The Globe and Mail reports in its Thursday edition that Prime Minister Justin Trudeau and Alberta Premier Danielle Smith traded barbed letters on Wednesday as Mr. Trudeau warned the province's proposal to withdraw from the Canada Pension Plan would harm pensioners, and pledged that his government will "do everything possible" to keep the CPP intact. The Globe's James Bradshaw writes that Mr. Trudeau said in a letter to Ms. Smith sent on Wednesday he is "deeply concerned" about the plan, which would see Alberta pull its share of assets from the CPP to set up a separate Alberta Pension Plan. He said it "would weaken the pensions of millions of seniors and hard-working people in Alberta and right across the country. The harm it would cause is undeniable." Ms. Smith's letter of retort told Mr. Trudeau it is "disingenuous and inappropriate for you to stoke fear in the hearts and minds of Canadian retirees on this issue." Ms. Smith has based her plans on a contentious report that estimated Alberta could be entitled to withdraw as much as $334-billion from the CPP by 2027 -- well over half the plan's $575-billion in assets -- according to calculations drawn up by Telus Health's LifeWorks that have drawn widespread criticism.