Investing.com - Republican efforts to push sweeping tax legislation through the U.S. Senate are heading towards a dramatic conclusion amid a new struggle over the scale of planned corporate tax cuts.Republican senators are considering whether to cut the corporate tax rate less deeply than President Donald Trump has demanded, a move that could make it easier to pass a tax overhaul bill without breaching their self-imposed deficit limits.Most of the reservations surrounding the bill center around limiting the impact of the tax bill on the U.S. budget deficit.Momentum towards a deal has been building this week after Senate Republicans voted to move the proposed bill to a debate on the floor. A final vote in the Senate could come as early as Thursday night.If passed, the Senate legislation would then need to be reconciled with a separate version already passed by the House of Representatives so a final bill could be sent to Trump to sign into law.Trump praised the tax plan to voters in a speech in Missouri on Wednesday, urging Congress to pass an overhaul that he said represents a once in a lifetime opportunity.