The contract can be terminated by either party with three months' notice.

合同的任何一方如提前三个月通知，均可终止本合同。

《牛津词典》

The election will decide if either party controls both houses of Congress.

这次选举将决定是否由任一党控制国会两院。

《柯林斯英汉双解大词典》

No failure by either party to enforce any rights hereunder shall be construed a waiver.

任何一方不履行其在本协议下的权利不应被视为弃权。

youdao

It was a party of protest, formed by men who refused to support either of the two old parties.

VOA: special.2010.06.03

If there are additional ideas from either party, I'm happy to consider them, as well.

WHITEHOUSE: Creating Jobs Through New Small Business Initiatives

And by no means are these kinds of actions a monopoly of either party.

FORBES: Brown Whitman Race Begs The Question: What's The Worst Thing That Can Happen?

But in most elections, that exasperation does not hurt or help either party disproportionately.

NPR: What Would It Take To Flip the House?