WASHINGTON - A seven-day Section 301 tariffs hearing wrapped up Tuesday after more than 300 business representatives had made their case against Washington's proposed additional tariffs on Chinese imports.

The overwhelming sentiment expressed by representatives from various sectors was that imposing additional tariffs up to 25 percent on about $300 billion worth of Chinese imports would significantly harm US businesses and consumers.

Speaking in a panel Tuesday afternoon, Water Sports Industry Association Executive Director Kevin Michael said 80 percent of life jackets sold in the United States are purchased from China, and any proposed tariffs would be largely passed on to US consumers, potentially heightening safety risks for water sport lovers.

"The increased duty and pricing would be a detriment to the goals to increase life jacket wear rates in order to prevent boating-related deaths," Michael said.

Answering repeated questions from trade officials on whether the businesses can switch to suppliers outside of China or move their manufacturing to the United States, representatives said such a proposal would face many hurdles.

Bill Sells, who represents the Sports and Fitness Industry Association, pointed to the baseball bats and gloves he brought and said the United States does not have the raw material to manufacture the goods, while production in other countries may not meet the safety standard.

"We don't really have another place to turn," Sells said.

The anti-tariff chorus rang well beyond the hearing hall, with major US companies and trade associations also decrying the tariffs.

In a recent letter addressed to US Trade Representative Robert Lighthizer, Tech giant Apple said that the proposed tariffs would impact all of its major products, including iPhone, iPad, Mac, AIRPods and Apple TV.

"We urge the US government not to impose tariffs on these products," the company said in the letter dated June 17, noting that it is one of the largest job creators in the country and the largest domestic corporate taxpayer to the US Department of the Treasury.

On June 13, a total of 520 American companies and 141 trade associations signed a letter to US President Donald Trump, urging his administration to abandon tariff hikes and reach a deal with China.

"We know firsthand that the additional tariffs will have a significant, negative and long-term impact on American businesses, farmers, families and the US economy," the letter said. "Tariffs are taxes paid directly by US companies."

It is unclear if the US government will heed the warning of US businesses and drop the tariff plan, but previous hearings of similar nature have shown that in most cases, officials at the US Trade Representative's Office (USTR) went ahead with the tariffs despite pleas from the US business community.

David Dollar, an economist and senior fellow at the Brookings Institution, argued that Washington's trade row strategy against China is "a poor one" and has "failed."

"The evidence to date is consistent with the view that the trade war with China is not likely to reduce the US trade deficit or bring manufacturing jobs back home," Dollar said, referring to two justifications the White House has given for pursuing protectionist trade policies against China.

US businesses will have to submit follow-up or supplementary comments by July 2, and a final decision may be reached by the USTR in the ensuing weeks.