BRASILIA, Dec 10 (Reuters) - With modified spending limits for Brazil"s government now set in its constitution, a new Treasury secretary told Reuters he sees recent calm in financial markets as a vote of confidence in fiscal discipline despite a volatile election year ahead. "The fiscal anchor is the same. It hasn"t changed. It"s the spending ceiling," said Special Treasury and Budget Secretary Esteves Colnago on Thursday in his first interview in the role. As he took the reins less than two months ago, the outlook was far from settled. Four senior Treasury officials including his predecessor had quit in protest over the new budget rules, and some speculated that Economy Minister Paulo Guedes was next. Brazil"s currency and stock market plunged on the prospect of a public spending spree ahead of the 2022 election. read more But Guedes vowed to stay on and swiftly appointed Colnago, a former planning minister and central bank analyst, to the key Treasury post. Both assured markets the government made a one-time change to budget rules without opening precedent for more. read more "When signs emerged that the constitutional amendment was about to be passed, markets calmed down," he said. On Wednesday, Congress approved the new constitutional budget cap, allowing 62 billion reais ($11 billion) of additional spending next year. New rules for court-ordered debts would make room for another 44 billion reais. The government is ramping up welfare spending promised by President Jair Bolsonaro ahead of next year"s presidential race. Colnago said policy debates surrounding the October election are likely to stir fresh volatility in markets next year, as some candidates have proposed a sharp break with current policy. "I think we will have volatility next year, which explains a little of the difference between our models for the next few years and some market models, because our model does not consider a change in the fiscal framework", he said. TARGETING DEBT Rather than a dramatic change, Colnago said the current Treasury team is pushing for an evolution of fiscal rules to target government debt levels rather than annual budget figures. "It"s an old dream of the Treasury," he said, explaining that current fiscal rules, including a primary budget target and the constitutional spending cap, are ultimately means for creating a sustainable debt trajectory. Despite a recent improvement in fiscal figures, Brazil"s gross debt has climbed past 80% of gross domestic product (GDP), well above the average of roughly 60% in emerging markets, according to data from the International Monetary Fund (IMF). An informal group of Treasury staff and congressional consultants has already begun discussing the proposal. Colnago said the idea is to promote a careful debate, listening to all actors, to avoid political blowback in an election year. As a result, discussions may not begin in earnest until the second half of 2022, said Colnago. "This will eventually be adopted in another government, not now," he said. Reporting by Marcela Ayres and Bernardo Caram Editing by Brad Haynes and Nick Zieminski