hold the balance of power idiom
举足轻重，掌握决定权
to be able to support either opposing side in a competition, etc. and therefore be able to decide who will win
If independents do end up holding the balance of power, then they decide whether Labor or the Liberals govern for the next four years. 如果无党派议员果真取得了举足轻重的地位，那么他们将决定由工党还是自由党来组成下一届四年期政府。