Trade unions and the Samyukt Kisan Morcha can effectively challenge the Central government's policies through various strategies:

• Mass protests and strikes: Organizing large-scale demonstrations, strikes, and protests can exert significant pressure on the government and draw attention to the concerns of workers and farmers.
• Coalition building: Collaborating with other opposition parties, NGOs, social organizations, and civil society groups can help amplify their voices and create a broader movement against government policies.
• Public awareness campaigns: Utilizing media, social platforms, and grassroots engagement, they can disseminate information about the negative impact of government policies on workers, farmers, and the general public.
• Legal challenges: Filing petitions in courts to challenge policies that are deemed unconstitutional or against the interests of workers and farmers can be an effective strategy to obtain judicial intervention.
• Engaging with policymakers: Lobbying and advocating for their interests directly with government officials, lawmakers, and policymakers can help raise concerns and influence decision-making.
• International support: Seeking solidarity and support from international trade unions and farmer organizations can increase the pressure on the Central government and draw attention to their cause globally.

By employing these strategies, trade unions and the Samyukt Kisan Morcha can effectively challenge the Central government's policies and advocate for the rights and welfare of workers and farmers.