AUGUSTA — The Legislature’s budget writing committee was poised to finish its work late Wednesday or early Thursday on a new two-year budget, with bleak prospects for any compromise between House Republicans and Democratic leaders on cuts to the state income tax. Without a late breakthrough, the 13-member Appropriations and Financial Affairs Committee is likely to depart from recent tradition and send a budget proposal to the full Legislature without unanimous support. In votes taken over the past week, the committee’s seven Democrats and two Republican senators have voted to increase funding for K-12 education, maintain municipal revenue sharing and continue the popular Homestead property tax credit program.