CREATE TABLE table_25276 ("Constituency" TEXT, "Winner" TEXT, "Party" TEXT, "Margin" FLOAT, "Runner-up a" TEXT, "Party a" TEXT)

Name the party a for m. s. k. sathiyendran runner up
SELECT "Party a" FROM table_25276 WHERE "Runner-up a" = 'M. S. K. Sathiyendran'
SELECT "Party a" FROM "table_25276" WHERE "Runner-up a" = 'M. S. K. Sathiyendran'