First term, 2008–2011 In 2008, McClay was selected as the
National Party candidate to stand for the
Rotorua electorate in the
2008 New Zealand general election, running against incumbent
Labour MP
Steve Chadwick. McClay won the seat of Rotorua on election night with a majority of 5,065 (15.43%). He was sworn in as a Member of Parliament on 8 December 2008. In 2009 his Shop Trading Hours Act 1990 Repeal (Easter Sunday Local Choice) Amendment Bill was drawn from the ballot. The bill would have allowed local authorities to permit shops to open on Easter Sunday – something currently prohibited in most of New Zealand. The bill was narrowly defeated at its first reading.
Second term, 2011–2014 In 2011, McClay was reelected as the Member of Parliament for Rotorua increasing his majority to 7,357 votes. In late June 2012, McClay announced his intention to bring a bill before Parliament to prohibit the display of gang insignia in all government premises, schools and hospitals in New Zealand. Modeled on the Whanganui Gang Insignia Act, McClay's announcement was met with strong public support. The Bill received Royal Assent on 12 August 2013 and became law the day after. On 30 August 2012, McClay voted against the
Marriage (Definition of Marriage) Amendment Bill, a bill allowing same-sex couples to marry in New Zealand. In 2013 he was appointed Minister of Revenue and Associate Minister of Health, serving outside of Cabinet. In January 2014, he was appointed Associate Minister for Tourism.
Third term, 2014–2017 In September 2014, McClay was again elected as Member of Parliament for Rotorua with an increased majority of 7,418, after beating
Labour candidate and former TV weatherman,
Tāmati Coffey. Following the 2014 election, McClay was promoted to Cabinet retaining his position as Minister of Revenue, while picking up the portfolios of State-Owned Enterprises, Associate Minister of Foreign Affairs and Associate Minister of Trade. Following the resignation of former Trade Minister
Tim Groser, McClay became Minister of Trade on 14 December 2015. He retained State Owned Enterprises and Associate Foreign Affairs, while handing over Inland Revenue to
Michael Woodhouse. In late July 2016, McClay was rebuked by Prime Minister
John Key for downplaying concerns that China would retaliate if New Zealand undertook an investigation of Chinese steel dumping. In 2017, McClay represented his party in Beijing before a dialogue organised by the
International Liaison Department of the
Chinese Communist Party (CCP). McClay also referred to the
Xinjiang internment camps as "vocational training centers" in line with CCP talking points.
Fourth term, 2017–2020 During the
2017 general election, McClay retained Rotorua for National by a margin of 7,901 votes. In late August 2019, former National MP
Jami-Lee Ross alleged that McClay had helped to facilitate a NZ$150,000 to the National Party in his capacity as Trade Minister in 2016 from a company owned by Chinese millionaire Lin Lang. McClay and the National Party have denied these allegations.
Fifth term, 2020–2023 During the
2020 general election, McClay retained his seat in Rotorua by a final margin of 825 votes. McClay was one of only eight MPs to vote against the
Conversion Practices Prohibition Legislation Act 2022. He voted against it at its first reading (which then-party-leader Judith Collins instructed her MPs to do), for it at its second reading, and against it at its third and final reading. Following a reshuffle in party leader
Christopher Luxon's
shadow cabinet on 19 January 2023, McClay was given the new Hunting and Fishing portfolio. He retained his 16th place ranking within Luxon's shadow cabinet. Following the announcement of Todd Muller's retirement from Parliament on 17 March 2023, McClay was given National's Agriculture portfolio and promoted to 12th place ranking within Luxon's shadow cabinet.
Sixth term, 2023–present During the
2023 general election, McClay retained his seat in Rotorua by an increased margin of 8,923 votes. In late November 2023, McClay was sworn in as a Minister taking responsibility of the
Agriculture,
Forestry, Hunting and Fishing, and
Trade portfolios. He was also appointed as the Associate Minister of Foreign Affairs. In mid December 2023, McClay accepted the role of Vice-Chair for the
World Trade Organization's 13th Ministerial Conference at
Abu Dhabi in 2024. On 11 June 2024, McClay confirmed that the Government would exclude agriculture from the NZ emissions trading scheme (ETS). On 14 June, McClay announced that the Government would cancel the annual service charges for forestry under the country's emissions trading scheme, which amounts to NZ$30.25 per hectare. On 30 July 2024, McClay apologised after telling
Green Party MP
Ricardo Menéndez March "you're not in Mexico now, we don't do things like that here" during a parliamentary sitting. March raised the matter with
Speaker Gerry Brownlee, who ordered McClay to withdraw and apologise. On 31 July, Prime Minister
Christopher Luxon described McClay's remarks as inappropriate and said he would discuss the matter with McClay.
Opposition leader Chris Hipkins described McClay's remarks as offensive towards migrant New Zealanders and questioned his suitability to remain as trade minister. As Trade Minister, McClay played a role in New Zealand securing
free trade agreements with the
United Arab Emirates in late September 2024 and the six-member
Gulf Cooperation Council in late October 2024. These free trade agreements lifted duties on the vast majority of New Zealand's exports to these Gulf Arab states over the next three to ten years. On 13 January 2025, McClay signed the comprehensive economic partnership agreement with the
United Arab Emirates, cutting tariffs on 98.5% of New Zealand exports to that country. In early August 2025, McClay travelled to Thailand and Indonesia to strengthen bilateral trade relations with the two Southeast Asian countries. Between 4 and 6 August, McClay visited Thailand where he met with
Thai Foreign Minister Maris Sangiampongsa to discuss bilateral cooperation in agricultural technology and tertiary education. On 7 August, McClay and
Indonesian Agriculture Minister Amran Sulaiman signed a new bilateral trade agreement to boost agricultural trade and cooperation between New Zealand and Indonesia. On 5 March 2026, McClay and the
Chilean Minister of Agriculture Ignacia Fernández Gatica signed a four-year bilateral agricultural agreement. In mid-March 2026, McClay hosted Irish
Minister of State Noel Grealish during his visit to New Zealand. The two leaders signed an agricultural climate research partnership agreement. On 27 April 2026, McClay signed the
New Zealand–India Free Trade Agreement with the Indian Commerce and Industry Minister
Piyush Goyal in
New Delhi. ==Personal life==